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A hybrid machine learning model for predicting continuous cooling transformation diagrams in welding heat-affected zone of low alloy steels

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Journal of Materials Science & Technology 2022年第12期107卷 207-215页

作者： Xiaoxiao geng Xinping Mao Hong-Hui Wu Shuize Wang Weihua xue Guanzhen Zhang Asad Ullah Hao Wang Beijing Advanced Innovation Center for Materials Genome Engineering Collaborative Innovation Center of Steel TechnologyUniversity of Science and Technology BeijingBeijing 100083China School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China School of Materials Science and Engineering Liaoning Technical UniversityFuxin 123000China Metals and Chemistry Research Institute China Academy of Railway SciencesBeijing 100081China Department of Mathematical Sciences Karakoram International UniversityGilgit-Baltistan15100Pakistan

Continuous cooling transformation diagrams in synthetic weld heat-affected zone(SH-CCT diagrams)show the phase transition temperature and hardness at different cooling rates,which is an important basis for formulating the welding process or predicting the performance of welding heat-affected ***,the experimental determination of SH-CCT diagrams is a time-consuming and costly process,which does not conform to the development trend of new *** addition,the prediction of SHCCT diagrams using metallurgical models remains a challenge due to the complexity of alloying elements and welding ***,in this study,a hybrid machine learning model consisting of multilayer perceptron classifier,k-Nearest Neighbors and random forest is established to predict the phase transformation temperature and hardness of low alloy steel using chemical composition and cooling *** the SH-CCT diagrams of 6 kinds of steels are calculated by the hybrid machine learning *** results show that the accuracy of the classification model is up to 100%,the predicted values of the regression models are in good agreement with the experimental results,with high correlation coefficient and low error ***,the mathematical expressions of hardness in welding heat-affected zone of low alloy steel are calculated by symbolic regression,which can quantitatively express the relationship between alloy composition,cooling time and *** study demonstrates the great potential of the material informatics in the field of welding technology.

关键词： Continuous cooling transformation Heat-affected zone Machine learning Symbolic regression

Establishment of Multiple Locus Variable-number Tandem Repeat Analysis Assay for Genotyping of Borrelia burgdorferi sensu lato Detected in China

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Biomedical and Environmental Sciences 2014年第9期27卷 665-675页

作者： ZHOU Xin HOU xue Xia geng Zhen ZHAO Rui WAN Kang Lin HAO Qin National Institute for Communicable Disease Control and Prevention State Key Laboratory for Infectious Disease Prevention and Control Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases Clinical Laboratory Center Shanxi provincial children and womenHospital

Objective Human Lyme Borreliosis （LB）, which is caused by Borrefia burgdorferi sensu lato （B. burgdorferi）, has been identified as a major arthropod-borne infectious disease in China. We aimed to develop a multiple locus variable-number tandem repeat （VNTR） analysis （MLVA） assay for the genotyping of Borrelia burgdorJ：eri strains detected in China. Methods B. garinii PBi complete 904.246 kb chromosome and two plasmids （cp26 and Ip54） were screened by using Tandem Repeats Finder program for getting potential VNTR loci, the potential VNTR loci were analyzed and identified with PCR and the VNTR loci data were analyzed and MLVA clustering tree were constrcted by using the categorical coefficient and the unweighted pair-group method with arithmetic means （UPGMA）. Results We identified 5 new VNTR loci through analyzing 47 potential VNTR loci. We used the MLVA protocol to analyse 101 B. burgdorferi strains detected in China and finally identified 51 unique genotypes in 4 major clusters including B. burgdorferi sensu stricto （B.b.s.s）, B. garinii, B. a[zelii, and B. valaisiana, consistent with the current MLSA phylogeny studies. The allele numbers of VNTR-1, VNTR-2, VNTR-3, VNTR-4, and VNTR-5 were 7, 3, 9, 7, and 6. The Hunter-Gaston index （HGI） of five VNTR loci were 0.79, 0.22, 0.77, 0.71, and 0.67, respectively. The combined HGI of five VNTR loci was 0.96. Clustering of the strains of Xinjiang, Inner Mongolia and Heilongjiang was confirmed, and this situation was consistent with the close geographical distribution of those provinces. Conclusion The MLVA protocol esytablished in this study is easy and can show strains＇ phylogenetic relationships to distinguish the strains of Borrelia species. It is useful for further phylogenetic and epidemiological analyses of Borrelia strains.

关键词： Borrelia burgdoferi sensu lato MLVA VNTR MLSA Genotyping

Performance improvement of n-i-p μc-Si:H solar cells by gradient hydrogen dilution technique

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Science China(Technological Sciences) 2009年第6期52卷 1756-1761页

作者： YUAN YuJie HOU GuoFu ZHANG JianJun xue JunMing CAO LiRan ZHAO Ying geng XinHua Key Laboratory of Optoelectronic Information Science and Technology of Ministry of Education Key Laboratory of Photo-Electronics Thin Film Devices and Technique of TianjinInstitute of Photo-Electronics Thin Film Devices and TechniqueNankai UniversityTianjin 300071China

High pressure radio frequency plasma enhanced chemical vapor deposition(RF-PECVD)process was adopted to investigate the effect of constant hydrogen dilution technique and gradient hydrogen dilu-tion technique on the structural evolution of intrinsic films and the performance of n-i-p microcrystal-line silicon solar *** experiment results demonstrated that the grain size and crystalline volume fraction along the growth direction of intrinsic films can be controlled and the performance of solar cells can be greatly improved by gradient hydrogen dilution *** initial active-area efficiency of 5.7%(Voc=0.47V,Jsc=20.2mA/cm2,FF=60%)for the μc-Si:H single-junction n-i-p solar cells and an initial active-area efficiency of 10.12%(Voc=1.2V,Jsc=12.05mA/cm2,FF=70%)for the a-Si:H/μc-Si:H tandem n-i-p solar cells has been achieved.

关键词： gradient hydrogen dilution technique microcrystalline silicon n-i-p solar cells

The multifunctional wound dressing with core-shell structured fibers prepared by coaxial electrospinning

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Frontiers of Materials Science 2016年第2期10卷 113-121页

作者： Qilin WEI Feiyang XU Xingjian XU xue geng Lin YE Aiying ZHANG Zengguo FENG School of Materials Science and Engineering Beijing Institute of Technology Beijing 100081 China Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications Beijing 100081 China

The non-woven wound dressing with core-shell structured fibers was prepared by coaxial electrospinning. The polycaprolactone （PCL） was electrospun as the fiber＇s core to provide mechanical strength whereas collagen was fabricated into the shell in order to utilize its good biocompatibility. Simultaneously, the silver nanoparticles （Ag- NPs） as anti-bacterial agent were loaded in the shell whereas the vitamin A palmitate （VA） as healing-promoting drug was encapsulated in the core. Resulting from the fiber＇s core- shell structure, the VA released from the core and Ag-NPs present in the shell can endow the dressing both heal-promoting and anti-bacteria ability simultaneously, which can greatly enhance the dressing＇s clinical therapeutic effect. The dressing can maintain high swelling ratio of 190% for 3 d indicating its potential application as wet dressing. Furthermore, the dressing＇s anti-bacteria ability against Staphylococcus aureus was proved by in vitro anti-bacteria test. The in vitro drug release test showed the sustainable release of VA within 72 h, while the cell attachment showed L929 cells can well attach on the dressing indicating its good biocompatibility. In conclusion, the fabricated nanofibrous dressing possesses multiple functions to benefit wound healing and shows promising potential for clinical application.

关键词： coaxial electrospinning core-shell structure multifunctional wounddressing anti-bacteria heal-promoting

Integrin beta 3-overexpressing mesenchymal stromal cells display enhanced homing and can reduce atherosclerotic plaque

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World Journal of Stem Cells 2023年第9期15卷 931-946页

作者： Hai-Juan Hu xue-Ru Xiao Tong Li De-Min Liu xue geng Mei Han Wei Cui First Division Department of CardiologyThe Second Hospital of Hebei Medical University and Institute of Cardiocerebrovascular Disease of Hebei ProvinceShijiazhuang 050000Hebei ProvinceChina Department of Obstetrics Shijiazhuang People's HospitalShijiazhuang 050030Hebei ProvinceChina Key Laboratory of Medical Biotechnology of Hebei Province Department of Biochemistry and Molecular BiologyCollege of Basic MedicineCardiovascular Medical Science CenterHebei Medical UniversityShijiazhuang 050017Hebei ProvinceChina

BACKGROUND Umbilical cord(UC)mesenchymal stem cell(MSC)transplantation is a potential therapeutic intervention for atherosclerotic vascular *** beta 3(ITGB3)promotes cell migration in several cell ***,whether ITGBmodified MSCs can migrate to plaque sites in vivo and play an anti-atherosclerotic role remains *** To investigate whether ITGB3-overexpressing MSCs(MSCs^(ITGB3))would exhibit improved homing efficacy in *** UC MSCs were isolated and *** vectors encoding ITGB3 or green fluorescent protein(GFP)as control were transfected into *** male apolipoprotein E-/-mice were acquired from Beijing Vital River Lab Animal Technology Co.,Ltd and fed with a high-fat diet(HFD)for 12 wk to induce the formation of atherosclerotic *** HFD-fed mice were randomly separated into three ***-labeled MSCs(MSCs^(GFP))or MSCs^(ITGB3)were transplanted into the mice intravenously via the tail *** staining,Oil red O staining,histological analyses,western blotting,enzymelinked immunosorbent assay,and quantitative real-time polymerase chain reaction were used for the *** ITGB3 modified MSCs successfully differentiated into the“osteocyte”and“adipocyte”phenotypes and were characterized by positive expression(>91.3%)of CD29,CD73,and CD105 and negative expression(<1.35%)of CD34 and Human Leukocyte *** a transwell assay,MSCs^(ITGB3)showed significantly faster migration than ***3 overexpression had no effects on MSC viability,differentiation,and *** staining revealed that ITGB3 overexpression substantially enhanced the homing of MSCs to plaque *** red O staining and histological analyses further confirmed the therapeutic effects of MSCs^(ITGB3),significantly reducing the plaque ***-linked immunosorbent assay and quantitative real-time polymerase chain reaction revealed that MSC^(ITGB3)transplantation considerably decr

关键词： Atherosclerosis Inflammation Integrin beta 3 Mesenchymal stem cells Arg-Gly-Asp structure Umbilical cord

Water Role and Its Influence on Hydrogen Isotopic Composition of Natural Gas during Gas Generation

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Acta Geologica Sinica(English Edition) 2011年第5期85卷 1203-1210页

作者： Jijun LI Shuangfang LU Wei WU Haitao xue Qingxia XU Jie geng Yinghua YU College of Earth Sciences Northeast Petroleum University Daqing Heilongjiang 163318 China Luliang Operating District of Xinjiang Oilfield Company Karamay Xinjiang 834000 China Exploration and Development Research Institute Daqing Oilfield Company Ltd. Daqing Heilongjiang 163712 China

In order to discuss the role and influence of water during the generation of natural gas,the participation mechanism of water during the evolution of organic matter and its influences were *** addition,we carried out an anhydrous cracking experiment of oil extracted from the Feixianguan Formation source rock in a closed system,which led to the establishment of the kinetic models for describing carbon and hydrogen isotopic fractionation during gas generation from organic *** models were calibrated and then applied to the northeastern Sichuan *** combining a series of gas generation experiments from octadecane pyrolysis without water or with distilled water in varying mass proportions,several results were proved:(1) the hydrogen isotopic composition of natural gas becomes lighter with the participation of formation water;(2) we can quantitatively study the hydrogen isotopic fractionation with the kinetic model for describing carbon isotopic fractionation; (3) more abundant and reliable geological information can be obtained through the combined application of carbon and hydrogen isotopic indices.

关键词： natural gas formation water free radical carbonium ion carbon and hydrogen isotopic fractionation kinetics

Emergy-based study on eco-economic system of arid and semi-arid region:a case of Gansu province,China

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Journal of Arid Land 2010年第3期2卷 207-213页

作者： xue, Bing Chen, XingPeng geng, Yong Yang, Mian Yang, FuXia Hu, XiaoFen Chinese Acad Sci Inst Appl Ecol Key Lab Pollut Ecol & Environm Engn Circular Econ & Ind Ecol Grp Shenyang 110016 Peoples R China Lanzhou Univ Coll Earth & Environm Sci Lanzhou 730000 Peoples R China Lanzhou Univ Sch Econ Lanzhou 730000 Peoples R China

Taking Gansu province as a model case,this study provides an integrated analysis on the eco-economic system of arid and semi-arid region based on emergy synthesis theory. Through calculating the values of renewable emergy flow,non-renewable resources,imported emergy,exported emergy,waste emergy,and total emergy during the period of 1978-2007,the performance of Gansu eco-economic system was analyzed. The results indicated that the renewable emergy flow within the province basically remained steady state which was estimated at 2.99×1022 solar emjoules (sej) from 1978 to 2007. The imported emergy and exported emergy were estimated at 3.75×1017 sej and 2.99×1020 sej in 1978 and increased to 1.07×1022 sej and 1.44×1022 sej respectively in 2007. The nonrenewable emergy flow was estimated at 1.62×1022 sej and increased to 1.85×1023 sej,with annual growth rate of 8.7%,while the estimated total emergy was 4.58×1022 sej in 1978 and increased to 2.11×1023 sej in 2007,with annual growth rate of 5.41%. Our results indicate a deteriorate situation between economic development and environmental protection in the region. The rapid economic growth in the past thirty years was based on a great consumption of nonrenewable resource and caused continuous decrease in the capacity of sustainable development. The environmental loading ratio was 0.53 in 1978,increased to 6.06 in 2007,indicating a rapid degradation of the regional environment quality. We calculated that the actual population was 1.53 times the renewable resource population in 1978,increased to 7.06 times in 2007. During the period of 1978-2007,the emergy rose from 2.45×1015 sej/(capita·a) to 8.07×1015 sej/(capita·a). Our analysis revealed that the emergy density presented a trend of gradual increase,and then the emergy currency ratio in Gansu decreased from 7.08×1013 sej/Chinese Yuan to 7.82×1012 sej/Chinese Yuan.

关键词： emergy analysis economic geography regional sustainable development arid and semi-arid area Gansu province

Changes in Sugar Metabolism and Fruit Quality of Different Pear Cultivars During Cold Storage

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Transactions of Tianjin University 2019年第4期25卷 389-399页

作者： Yanan Zhao Jinhui geng Ying Zhang Kyongil Nam Zhaohui xue Xiaohong Kou School of Chemical Engineering and Technology Tianjin UniversityTianjin 300354China College of Food Technology Han Dok Su Pyongyang Light Industry UniversityPyongyang 999093Democratic People’s Republic of Korea

This study evaluated the changes in sugar metabolism and fruit quality of diff erent pear cultivars during cold storage using seven major commercial pear cultivars belonging to diff erent Pyrus species, such as P. bretschneideri Rehd.("Huangguan,""Yali"), P. pyrifolia Nakai.("Wonhwang,""Hosui"), P. ussuriensis Maxim.("Jingbai,""Nanguo"), and P. communis L.("Bartlett"). The fi rmness, respiration rate, titratable acidity, total soluble solids, sugar content, and enzyme activity of the seven pear cultivars were investigated. SPSS was used for analyzing the signifi cance of diff erent indexes. Results showed that fructose was the dominant sugar, accounting for > 60% of total sugars, followed by glucose and sucrose. The respiration peak of almost all cultivars appeared within 60 days. The levels of fructose, glucose, sucrose, and total soluble solids increased within 90 days and then generally decreased. Acid invertase showed the highest activity among all pear cultivars, followed by neutral invertase, sucrose synthetase, and sucrose phosphate synthetase during storage.

关键词： Pear cultivar Sugar metabolism Enzyme activity Quality change

MicroRNAs and their role in viral infection

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Frontiers in Biology 2007年第1期2卷 15-20页

作者： MU Junjie YAO xue CHEN Qimin geng Yunqi QIAO Wentao College of Life Science and Tianjin State Laboratory of Microbial Functional Genomics Nankai UniversityTianjin 300071China

Recently,a class of about 22 nucleotides(nt)small RNA has been discovered in many eukaryotes,termed microRNAs(miRNAs),which have a variety of *** recent findings have demonstrated that viruses can also encode their own ***,other findings reveal a relationship between host miRNA and viral *** findings suggest a tight relationship between host and viral infection via miRNA *** article introduces the miRNAs encoded by viruses and reviews the advances of the interaction of the mammalian host miRNAs and viral infection.

关键词： microRNA(miRNA) viral infection small RNA