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Mechanism of α-Cr precipitation and crystallographic relationships between α-Cr and δ phases in Inconel 718 alloy after long-time thermal exposure

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International Journal of Minerals,Metallurgy and Materials 2010年第3期17卷 312-317页

作者： Zhong-nan Bi Jian-xin Dong Mai-cang Zhang Lei zheng Xi-shan Xie School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

To study the precipitation mechanism of α-Cr phase in Inconel 718 alloy, the samples after long-time aging at 650 and 677℃ were examined by microstructural observations and chemical phase analysis methods. Combining the thermodynamics and kinetics calculation results, α-Cr always precipitates in the vicinity of δ phase, because δ phase rejects Cr into the γ-matrix when growing. The selected area diffraction patterns confirm that the crystallographic relationships of α-Cr with 6 phase are （010）d/（1- 10）*** and [100]d/If 11 ]α-Cr- A graphic model is also presented to show the crystallographic relation between α-Cr and δ phases.

关键词： Inconel 718 precipitation mechanism crystallography thermodynamics kinetics

A flexible model-free tram signal priority method with a large coordination scope in China

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Transportation Safety and Environment 2024年第3期6卷 28-34页

作者： shan Wang shanghai Urban Construction Design and Research Institute No.3447 Dongfang RoadPudong DistrictShanghai 200125China

Tram systems with the advantages of reliable operation,comfort,low emissions and moderate capacity have been quite popular in recent years in ***,there are still problems with tram signal control(*** model,signal control strategies).In-depth analysis on existing operational issues of trams,calculation of two evaluation indexes,as well as a flexible model-free tram signal priority method were developed to deal with tram *** research in Songjiang District,shanghai shows that:(1)The function of the green extension strategy is limited with c.a.10%tram priority improvement,while the optimal one can reach to 85%higher on average.(2)A scheme with a benefit for trams and with no negative impact,and even benefits,for general traffic can be realized.(3)The optimal solution is beneficial for intersections with a maximum c.a.70%amelioration with delay decreasing from 132.7 s/vehicle to 40.89 s/vehicle,or from 104.77 s/capita to 22.31 s/*** paper has great significance for the signal optimization and safety of tram systems,even the development of a comprehensive transportation system for a city.

关键词： tram signal priority large coordination scope model-free signal control average passenger delay average vehicle delay

Effect of temperature on the demography of Galerucella birmanica （Coleoptera： Chrysomelidae）

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Insect Science 2008年第4期15卷 375-380页

作者： Fu-shan zheng Yu-Zhou Du Zhi-Jie Wang Jia-Jun Xu Institute of Applied Entomology Yangzhou University Yangzhou Jiangsu Province Laiwu Vocational Technology Institute Laiwu Shandong Province China

Studies on the effect of temperature on the development of the water chestnut beetle, Galerucella birmanica Jacoby were carried out in the laboratory at seven different temperatures： 16 ℃, 19 ℃, 22 ℃, 25 ℃, 28 ℃, 31 ℃ and 34 ℃. The developmental time decreased with increase in temperature. The developmental time at 16 ℃, 19℃, 22 ℃, 25 ℃, 28 ℃, 31 ℃ and 34 ℃ was 96.60, 80.68, 58.96, 43.48, 35.03, 30.08 and 28.02 days for the period from egg hatching to adult emergence, respectively. The developmental threshold estimated for a generation by linear regression was 10.36℃. The fecundity per female at 22 ℃, 25 ℃, 28 ℃, 31 ℃ and 34 ℃ was 102.3, 134.5, 141.2, 130.1 and 116.2 eggs, respectively. Oviposition period ranged from 15.6 days at 22 ℃ to 8.6 days at 34 ℃. Hatchability of eggs was highest at 31 ℃ with 76.9% and lowest at 34 ℃ with 57.1%. The highest generation survival rate was 65.3% at 31 ℃, and the intrinsic rate of natural increase （rm） for G. birmanica was the highest at 34 ℃.

关键词： demography developmental threshold fecundity Galerucella birmanicaJacoby longevity survivorship temperature

Isolation and Structural Analysis of an Acidic Polysaccharide from Astragalus membranaceus （Fisch.） Bunge

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Journal of Integrative Plant Biology 2006年第11期48卷 1379-1384页

作者： Shun-Chun Wang Jun-Jie shan zheng-Tao Wang Zhi-Bi Hu Institute of Chinese Materia Medica Shanghai University of Traditional Chinese Medicine Shanghai 201203 China

A new water-soluble hetero-polysaccharlde, APSID3, was obtained from a hot-water extract of the roots of Astragalus membranaceus （Flsch.） Bunge by DEAE-Sepharose Fast Flow and Sephacryl S-300 chromatography. The molecular weight of APSID3 was estimated to be 5.79 × 10^5 Da. Based on a sugar composlUon analysis, methylatlon analysis, partial hydrolysis and 13C nuclear magnetic resonance experimentation, It was concluded that the minimal repeat unit of APSID3 was composed of one terminal arablnose, one 1,5-1Inked arabinose, one 1,3-1Inked rhamnose, one 1,3,4-1Inked rhamnose, five 1,4-1Inked methyl galacturonates and six 1,4-1inked methyl glucuronates.

关键词： Astragalus membranaceus hetero-polysaccharide isolation and purification structural analysis.

The Weather Temperature and Air Pollution Interaction and Its Effect on Hospital Admissions due to Respiratory System Diseases in Western China

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Biomedical and Environmental Sciences 2013年第5期26卷 403-407页

作者： WANG Min Zhen zheng shan WANG Shi Gong TAO Yan shanG Ke zheng College of Atmospheric Sciences Lanzhou University The Gansu Key Laboratory of Arid Climate Change and Reducing Disaster College of Earth and Environmental Sciences Lanzhou University

Air pollution has ever become a global major public health *** studies showed that air pollution is associated with excessive mortality and morbidity of respiratory disease[1-2].The extreme weather temperature can impact human health and the thermal stresses can lead not only to direct deaths and illnesses,but also to aggravation of respiratory disease[3-4].Though the independent

关键词： The Weather Temperature and Air Pollution Interaction and Its Effect on Hospital Admissions due to Respiratory System Diseases in Western China

A whole-net cooperative positioning method based on CDGNSS and inter-vehicle ranging

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Chinese Journal of Aeronautics 2024年第2期37卷 401-416页

作者： shan HU Hongbo ZHAO Chen ZHUANG School of Electronics and Information Engineering Beihang UniversityBeijing 100191China

Relative positioning is recognized as an important issue for vehicles in urban ***-vehicle Cooperative Positioning(CP)techniques which fuse the Global Navigation Satellite System(GNSS)and inter-vehicle ranging have attracted attention in improving the performance of baseline estimation between ***,current CP methods estimate the baselines separately and ignore the interactions among the positioning information of different *** interactions are called’information coupling’.In this work,we propose a new multivehicle precise CP framework using the coupled information in the network based on the Carrier Differential GNSS(CDGNSS)and inter-vehicle *** demonstrate the benefit of the coupled information by deriving the Cramer-Rao Lower Bound(CRLB)of the float estimation in *** fully use this coupled information,we propose a Whole-Net CP(WN-CP)method which consists of the Whole-Net Extended Kalman Filter(WN-EKF)as the float estimation filter,and the Partial Baseline Fixing(PBF)as the ambiguity resolution *** WN-EKF fuses the measurements of all baselines simultaneously to improve the performance of float estimation,and the PBF strategy fixes the ambiguities of the one baseline to be estimated,instead of full ambiguity resolution,to reduce the computation load of ambiguity *** tests involving four vehicles were conducted in urban *** results show that the proposed WN-CP method can achieve better performance and meanwhile maintain a low computation load compared to the existing methods.

关键词： GNSS Cooperative positioning Baseline Ambiguity resolution Information coupling

Research on the macro-and meso-mechanical properties of frozen sand mold based on Hertz-Mindlin with Bonding model

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Particuology 2024年第5期88卷 176-191页

作者： Jianpei Shi Zhongde shan Haoqin Yang College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China College of Material Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016China

In this study,macro-and meso-mechanical properties of frozen sand molds were discussed based on the Hertz-Mindlin with Bonding(HMB)***-Burman,steepest ascent,and central composite designs were utilized to propose a parameter calibration *** effects of mesoscopic parameter variations on the compressive strength and average gradient of stress-strain were investigated through response surface method *** showed that the relative error between the simulated and measured repose angle is 3.1%under calibrated intrinsic contact *** compressive strength and average stress-strain gradient primarily depend on the normal and shear stiffness per unit area,as well as the particle size and porosity of the silica ***,taking load-displacement curves of three frozen sand molds with different geometric characteristics as the target value,the reliability and effectiveness of the frozen sand mold HMB model were verified through uniaxial compression tests and discrete element simulations.

关键词： Frozen sand mold Hertz-Mindlin with Bonding model Uniaxial compression test Discrete element method Mechanical properties

Male reproductive function before and after the adjustment of the COVID-19 prevention policy:a multicenter study in China

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Asian Journal of Andrology 2024年第3期26卷 308-314页

作者： Jian-zheng Li Han Wu Li Wang Yun-shan Wang Feng Kong Long-Qiao Cao Ming Liang Xiong Wang Ming-Zhen Yuan shandong Provincial Hospital Affiliated to shandong First Medical University Jinan 250000China Institute of Women Children and Reproductive HealthShandong UniversityJinan 250012China Engineering Laboratory of Urinary Organ and Functional Reconstruction of shandong Province Jinan 250000China The First People’sHospital of Jining Jining 272000China Department of Reproductive Medicine The Second Affiliated Hospital of Shandong University of Traditional Chinese MedicineJinan 250000China Reproductive Medicine Center Affiliated Yantai Yuhuangding Hospital of Qingdao UniversityYantai 264000China

At the end of 2022,the adjustment of the coronavirus disease 2019(COVID-19)pandemic control policy in China resulted in alarge-scale increase in public *** compare the fertility parameters of male patients before and after the adjustments ofthe COVID-19 pandemic control policy in China,we collected data on patients’medical histories and laboratory examinations ontheir first visits between June 2022 and March 2023 in five different *** were divided into five groups according tothe timeline of the policy *** data we collected from male patients included semen quality and serum reproductivehormone levels,and intergroup comparisons were made using the Mann–Whitney U and Chi-square *** total,16784 casesunderwent regular semen analysis,11180 had sperm morphology assessments,and 7200 had reproductive hormone *** showed declining trends in semen volume,sperm motility,and the progressive sperm motility rate after the policy *** comparison revealed an initial decrease and gradual recovery in progressive motility *** morphology analysisshowed increased neck and tail abnormalities after the policy *** significant change in hormone levels was *** the adjustment of the COVID-19 prevention policy in China,a decline in sperm motility and morphology was *** trend may gradually recover over 2 *** the policy adjustment,reproductive hormone levels were relatively stablethroughout,except for an increase in luteinizing hormone(LH).These changes in semen parameters suggest that the policyadjustment had a short-to medium-term impact on male reproductive function.

关键词： COVID-19 multicenter study reproduction SARS-CoV-2 semen analysis

Synthesis and Characterization of Layered Co_2(OH)_3(CH_3COO)·H_2O

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Chemical Research in Chinese Universities 2011年第6期27卷 910-914页

作者： zheng De-shan WANG Yan-zhong SHI Li-min SUN Si-xiu School of Materials and Chemical Engineering Xi＇an Technological University Xi＇an 710032 P. R. China School of Chemistry and Chemical Engineering Shandong University Jinan 250100 P. R. China

Layered hydroxide metal acetate Co2（OH）3（CH3COO）·H2O with an interlayer spacing of 1.282 nm has been synthesized by a novel method which is employed in ethanol-aqueous mixed solvents media. Experiment results show that the purity of the product by the modified method is higher compared with that by the previous methods. A complete characterization of the as-prepared samples was performed by means of X-ray powder diffraction, IR spectroscopy, scanning electron microscope, as well as magnetic measurement. The facile and effective approach for the preparation of this compound in this study is very interesting and important because it has wide application in the field of anionic exchange reaction for the synthesis of hybrid organic-inorganic compounds.

关键词： Anionic exchange reaction Hybrid organic-inorganic compound Layered hydroxide cobalt acetate Magnetic property