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Underdetermined direction of arrival estimation with nonuniform linear motion sampling based on a small unmanned aerial vehicle platform

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Defence Technology（防务技术） 2024年第3期33卷 352-363页

作者： Xinwei Wang Xiaopeng yan tai An Qile Chen Dingkun Huang Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing 100081China

Uniform linear array(ULA)radars are widely used in the collision-avoidance radar systems of small unmanned aerial vehicles(UAVs).In practice,a ULA's multi-target direction of arrival(DOA)estimation performance suffers from significant performance degradation owing to the limited number of physical elements.To improve the underdetermined DOA estimation performance of a ULA radar mounted on a small UAV platform,we propose a nonuniform linear motion sampling underdetermined DOA estimation method.Using the motion of the UAV platform,the echo signal is sampled at different positions.Then,according to the concept of difference co-array,a virtual ULA with multiple array elements and a large aperture is synthesized to increase the degrees of freedom(DOFs).Through position analysis of the original and motion arrays,we propose a nonuniform linear motion sampling method based on ULA for determining the optimal DOFs.Under the condition of no increase in the aperture of the physical array,the proposed method obtains a high DOF with fewer sampling runs and greatly improves the underdetermined DOA estimation performance of ULA.The results of numerical simulations conducted herein verify the superior performance of the proposed method.

关键词： Unmanned aerial vehicle(UAV) Uniform linear array(ULA) Direction of arrival(DOA) Difference co-array Nonuniform linear motion sampling method

Automatic modulation recognition of radio fuzes using a DR2D-based adaptive denoising method and textural feature extraction

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Defence Technology（防务技术） 2024年第4期34卷 328-338页

作者： yangtian Liu Xiaopeng yan Qiang Liu tai An Jian Dai Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing 100081China China Research and Development Academy of Machinery Equipment Beijing 100089China

The identification of intercepted radio fuze modulation types is a prerequisite for decision-making in interference systems.However,the electromagnetic environment of modern battlefields is complex,and the signal-to-noise ratio(SNR)of such environments is usually low,which makes it difficult to implement accurate recognition of radio fuzes.To solve the above problem,a radio fuze automatic modulation recognition(AMR)method for low-SNR environments is proposed.First,an adaptive denoising algorithm based on data rearrangement and the two-dimensional(2D)fast Fourier transform(FFT)(DR2D)is used to reduce the noise of the intercepted radio fuze intermediate frequency(IF)signal.Then,the textural features of the denoised IF signal rearranged data matrix are extracted from the statistical indicator vectors of gray-level cooccurrence matrices(GLCMs),and support vector machines(SVMs)are used for classification.The DR2D-based adaptive denoising algorithm achieves an average correlation coefficient of more than 0.76 for ten fuze types under SNRs of-10 d B and above,which is higher than that of other typical algorithms.The trained SVM classification model achieves an average recognition accuracy of more than 96%on seven modulation types and recognition accuracies of more than 94%on each modulation type under SNRs of-12 d B and above,which represents a good AMR performance of radio fuzes under low SNRs.

关键词： Automatic modulation recognition Adaptive denoising Data rearrangement and the 2D FFT(DR2D) Radio fuze

Search for the Metal-weak Thick Disk from the LAMOST DR5

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Research in Astronomy and Astrophysics 2022年第2期22卷 72-85页

作者： tai-sheng yan Jian-Rong Shi Hao Tian Wei Zhang Bo Zhang Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100012China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China Key Laboratory of Space Astronomy and Technology National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Department of Astronomy Beijing Normal UniversityBeijing 100875China

Based on the data release of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope survey(LAMOST DR5)and the Gaia Early Data Release 3(Gaia EDR3),we construct a sample containing 46,109 giant(log g≤3.5 dex)stars with heliocentric distance d≤4 kpc,and the sample is further divided into two groups of the inner(RGC8.34 kpc).The LZdistributions of our program stars in the panels with different[Fe/H]and[α/Fe]suggest that the thick-disk consists of two distinct components with different chemical compositions and kinematic properties.For the inner region,the metal-weak thick disk(MWTD)significantly contributes when[α/Fe]>+0.2 dex and[Fe/H]-0.8 dex.However,MWTD clearly appears only when[α/Fe]>+0.2 dex and[Fe/H]tained from the V_(φ)distribution.The higher fraction of MWTD in the inner region than that in the outer region implies that MWTD may form in the inner disk,and is observational evidence about the inside-out disk formation scenario.

关键词： stars:abundances stars:atmospheres Galaxy:structure Galaxy:kinematics and dynamics methods:data analysis

Xuebijing improves intestinal microcirculation dysfunction in septic rats by regulating the VEGF-A/PI3K/Akt signaling pathway

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World Journal of Emergency Medicine 2024年第3期15卷 206-213页

作者： A-ling Tang yan Li Li-chao Sun Xiao-yu Liu Nan Gao sheng-tao yan Guo-qiang Zhang Department of Emergency China-Japan Friendship HospitalBeijing 100029China Graduate School Beijing University of Chinese MedicineBeijing 100105China

BACKGROUND:This study aims to explore whether Xuebijing(XBJ) can improve intestinal microcirculation dysfunction in sepsis and its mechanism.METHODS:A rat model of sepsis was established by cecal ligation and puncture(CLP).A total of 30 male SD rats were divided into four groups:sham group,CLP group,XBJ + axitinib group,and XBJ group.XBJ was intraperitoneally injected 2 h before CLP.Hemodynamic data(blood pressure and heart rate) were recorded.The intestinal microcirculation data of the rats were analyzed via microcirculation imaging.Enzyme-linked immunosorbent assay(ELISA) kits were used to detect the serum levels of interleukin-6(IL-6),C-reactive protein(CRP),and tumor necrosis factor-α(TNF-α) in the rats.Histological analysis and transmission electron microscopy were used to analyze the injury of small intestinal microvascular endothelial cells and small intestinal mucosa in rats.The expression of vascular endothelial growth factor A(VEGF-A),phosphoinositide 3-kinase(PI3K),phosphorylated PI3K(p-PI3K),protein kinase B(Akt),and phosphorylated Akt(p-Akt) in the small intestine was analyzed via Western blotting.RESULTS:XBJ improved intestinal microcirculation dysfunction in septic rats,alleviated the injury of small intestinal microvascular endothelial cells and small intestinal mucosa,and reduced the systemic inflammatory response.Moreover,XBJ upregulated the expression of VEGF-A,p-PI3K/total PI3K,and p-Akt/total Akt in the rat small intestine.CONCLUSION:XBJ may improve intestinal microcirculation dysfunction in septic rats possibly through the VEGF-A/PI3K/Akt signaling pathway.

关键词： Sepsis Xuebijing Vascular endothelial growth factor A Microcirculation Rat Phosphoinositide 3-kinase Protein kinase B

Dietary fiber intake and its association with diabetic kidney disease in American adults with diabetes:A cross-sectional study

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World Journal of Diabetes 2024年第3期15卷 475-487页

作者： Xin-Hua Jia sheng-yan Wang Ai-Qin Sun Department of Critical Care Medicine Dezhou People’s HospitalDezhou 253000Shandong ProvinceChina Emergency Intensive Care Unit Dezhou People’s HospitalDezhou 253000Shandong ProvinceChina

BACKGROUND Dietary fiber(DF)intake may have a protective effect against type 2 diabetes(T2D);however,its relationship with diabetic kidney disease(DKD)remains unclear.AIM To investigate the potential association between DF intake and the prevalence of DKD in individuals diagnosed with T2D.METHODS This cross-sectional study used data from the National Health and Nutrition Examination Survey collected between 2005 and 2018.DF intake was assessed through 24-h dietary recall interviews,and DKD diagnosis in individuals with T2D was based on predefined criteria,including albuminuria,impaired glomerular filtration rate,or a combination of both.Logistic regression analysis was used to assess the association between DF intake and DKD,and comprehensive subgroup and sensitivity analyses were performed.RESULTS Among the 6032 participants,38.4%had DKD.With lower DF intake-T1(≤6.4 g/1000 kcal/day)-as a reference,the adjusted odds ratio for DF and DKD for levels T2(6.5-10.0 g/1000 kcal/day)and T3(≥10.1 g/1000 kcal/day)were 0.97(95%CI:0.84-1.12,P=0.674)and 0.79(95%CI:0.68-0.92,P=0.002),respectively.The subgroup analysis yielded consistent results across various demographic and health-related subgroups,with no statistically significant interactions(all P>0.05).CONCLUSION In United States adults with T2D,increased DF intake may be related to reduced DKD incidence.Further research is required to confirm these findings.

关键词： Dietary fiber Diabetic kidney disease Type 2 diabetes National Health and Nutrition Examination Survey Crosssectional study

Organic near-infrared optoelectronic materials and devices:an overview

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Advanced Photonics 2024年第1期6卷 17-42页

作者： Zong-Lu Che Chang-Cun yan Xue-Dong Wang Liang-sheng Liao Soochow University Institute of Functional Nano and Soft Materials(FUNSOM)Jiangsu Key Laboratory for Carbon-Based Functional Materials and DevicesSuzhouChina Soochow University College of ChemistryChemical Engineering and Materials ScienceJiangsu Engineering Laboratory of Novel Functional Polymeric MaterialsSuzhouChina Macao University of Science and Technology Macao Institute of Materials Science and EngineeringMacaoChina

Near-infrared(NIR)light has shown great potential for military and civilian applications owing to its advantages in the composition of sunlight,invisibility to human eyes,deeper penetration into biological tissues,and low optical loss in optical fibers.Therefore,organic optoelectronic materials that can absorb or emit NIR light have aroused great scientific interest in basic science and practical applications.Based on these NIR organic optoelectronic materials,NIR optoelectronic devices have been greatly improved in performance and application.In this review,the representative NIR organic optoelectronic materials used in organic solar cells,organic photodetectors,organic light-emitting diodes,organic lasers,and organic optical waveguide devices are briefly introduced,and the potential applications of each kind of device are briefly summarized.Finally,we summarize and take up the development of NIR organic optoelectronic materials and devices.

关键词： near-infrared organic optoelectronic materials organic solar cells organic light-emitting devices organic optical waveguides

Development of a prognostic scoring system for hepatic vena cava Budd-Chiari syndrome with hepatocellular carcinoma

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Hepatobiliary & Pancreatic Diseases International 2024年第4期23卷 370-375页

作者： sheng-yan Liu Lu-Hao Li Zhao-Chen Liu Su-Xin Li Xiao-Wei Dang Department of Hepatopancreatobiliary Surgery the First Affiliated Hospital of Zhengzhou UniversityZhengzhou 450052China Budd-Chiari Syndrome Diagnosis and Treatment Center of Henan Province Zhengzhou 450052China

Background:Hepatocellular carcinoma(HCC)is a serious complication of hepatic vena cava Budd-Chiari syndrome(HVC-BCS)that significantly reduces the survival time of patients.Our study aimed to analyze the prognostic factors influencing the survival of HVC-BCS patients with HCC and to develop a prognostic scoring system.Methods:The clinical and follow-up data of 64 HVC-BCS patients with HCC who received invasive treatment at the First Affiliated Hospital of Zhengzhou University between January 2015 and December 2019 were retrospectively analyzed.Kaplan-Meier curves and log-rank tests were used to analyze the survival curve of patients and the difference in prognoses between the groups.Univariate and multivariate Cox regression analyses were performed to analyze the influence of biochemical,tumor,and etiological characteristics on the total survival time of patients,and a new prognostic scoring system was developed according to the regression coefficients of the independent predictors in the statistical model.The prediction efficiency was evaluated using the time-dependent receiver operating characteristics curve and concordance index.Results:Multivariate analysis showed that serum albumin level7 cm(HR=8.623,95%CI:3.771-19.715,P<0.001),and inferior vena cava stenosis(HR=3.612,95%CI:1.646-7.928,P=0.001)were independent predictors of survival.A prognostic scoring system was developed according to the above-mentioned independent predictors,and patients were classified into grades A,B,C and D.Significant differences in survival were found among the four groups.Conclusions:This study successfully developed a prognostic scoring system for HVC-BCS patients with HCC,which is helpful for clinical evaluation of patient prognosis.

关键词： Budd-Chiari syndrome Hepatocellular carcinoma Prognostic factors Inferior vena cava stenosis Prognostic scoring system

Conquer coronary artery perforation with magic hands

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Journal of Geriatric Cardiology 2024年第4期21卷 379-386页

作者： Yi-Lun ZOU Jian-Qiang LI Ding-Yu WANG Yong-tai GONG Li sheng Yue LI Department of Cardiology the First Affiliated Hospital of Harbin Medical UniversityHarbinChina

Coronary artery perforation(CAP) poses a significant challenge for interventional cardiologists. Management of CAP depends on the location and severity of the perforation. The conventional method for addressing the perforation of large vessels involves the placement of a covered stent, while the perforation of distal and collateral vessels is typically managed using coils, autologous skin, subcutaneous fat, microspheres, gelatin sponge, thrombin or other substances. However, the above techniques have certain limitations and are not applicable in all scenarios. Our team has developed a range of innovative strategies for effectively managing CAP. This article provides an insightful review of the various tips and tricks for the treatment of CAP.

关键词： coronary sponge perforation

Bipolar hip arthroplasty using conjoined tendon preserving posterior lateral approach in treatment of displaced femoral neck fractures

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World Journal of Clinical Cases 2024年第6期12卷 1076-1083页

作者： Ting-Xin yan sheng-Jie Dong Bo Ning Yu-Chi Zhao Department of Joint Surgery Yantaishan HospitalYantai 264003Shandong ProvinceChina Department of Joint Surgery Dongying People's HospitalDongying 257091Shandong ProvinceChina

BACKGROUND Hip fractures account for 23.8%of all fractures in patients over the age of 75 years.More than half of these patients are older than 80 years.Bipolar hemiarthroplasty(BHA)was established as an effective management option for these patients.Various approaches can be used for the BHA procedure.However,there is a high risk of postoperative dislocation.The conjoined tendon-preserving posterior(CPP)lateral approach was introduced to reduce postoperative dislocation rates.AIM To evaluate the effectiveness and safety of the CPP lateral approach for BHA in elderly patients.METHODS We retrospectively analyzed medical data from 80 patients with displaced femoral neck fractures who underwent BHA.The patients were followed up for at least 1 year.Among the 80 patients,57(71.3%)were female.The time to operation averaged 2.3 d(range:1-5 d).The mean age was 80.5 years(range:67-90 years),and the mean body mass index was 24.9 kg/m^(2)(range:17-36 kg/m^(2)).According to the Garden classification,42.5%of patients were typeⅢand 57.5%of patients were typeⅣ.Uncemented bipolar hip prostheses were used for all patients.Torn conjoined tendons,dislocations,and adverse complications during and after surgery were recorded.RESULTS The mean postoperative follow-up time was 15.3 months(range:12-18 months).The average surgery time was 52 min(range:40-70 min)with an average blood loss of 120 mL(range:80-320 mL).The transfusion rate was 10%(8 of 80 patients).The gemellus inferior was torn in 4 patients(5%),while it was difficult to identify in 2 patients(2.5%)during surgery.The posterior capsule was punctured by the fractured femoral neck in 3 patients,but the conjoined tendon and the piriformis tendon remained intact.No patients had stem varus greater than 3 degrees or femoral fracture.There were no patients with stem subsidence more than 5 mm at the last follow-up.No postoperative dislocations were observed throughout the follow-up period.No significance was found between preoperative and postoperative mean Health Service System score

关键词： Conjoined tendon preserving Bipolar hip arthroplasty Femoral neck fractures Postoperative dislocation Posterolateral approach