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Genesis and Implications of the Composition and Sedimentary Structure of Fine-Grained Carbonate Rocks in the Shulu Sag

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Journal of Earth Science 2017年第6期28卷 1047-1063页

作者： Xiangxin Kong Zaixing Jiang Chao Han lijing zheng Yiming Zhang Ruifeng Zhang Jianzhang Tian School of Energy Resources China University of Geosciences Beijing 100083 China Institute of Earth Sciences China University of Geosciences Beijing 100083 China College of Earth Science and Engineering Shandong University of Science and Technology Qingdao 266590 China Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China PetroChina Huabei Oilfield Company Renqiu 062552 China

Fine-grained carbonate rocks, which extensively occur in the Eocene strata in the Shulu sag, Bohai Bay Basin, North China, represent an unconventional, fine-grained carbonate reservoir. However, previous studies have ignored the complexity of the lithofacies components and their formation mechanisms. Fine-grained carbonate rocks are typical reservoirs in which hydrocarbons form and gather. A better understanding of the nature of these rocks is extremely important for evaluating the quality of unconventional, fine-grained carbonate reservoirs. Various lithofacies components were discriminated in this study with a combination of petrographic observations and carbon isotope analyses. These finegrained carbonate rocks comprise terrigenous, biogenic and diagenetic materials. Terrigenous input and biologically induced precipitation are the main sources of the materials in the lake. Five lithofacies were identified based on the observations of sedimentary features（core and thin section） and mineralogical data：（1） varve-like laminated calcilutite,（2） graded laminated calcilutite,（3） interlaminated calcisiltitecalcilutite,（4） massive calcilutite, and（5） massive calcisiltite-calcarenite. Their origins were recorded by various lithofacies components, which are controlled by the interactions of physical, chemical and biological processes. This study indicated that the lithology of the bedrocks was the key factor controlling carbonate accumulation. The tectonics and climate can influence the weathering and types of lithofacies. Primary productivity controlled the precipitation of the endogenic calcite. These factors jointly determined the abundant fine-grained carbonate rocks that have accumulated in the Shulu sag.

关键词： fine-grained carbonate rocks terrigenous materials biologically induced precipitation varve carbon isotope massive calcilutite

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Detection of new antibiotic resistance gene profile in Escherichia coliassociated with avian leukosis virus infection from broiler chickens

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BIOCELL 2020年第2期44卷 217-224页

作者： HAIFENG WANG JUAN GUO lijing zheng SHUYING LIU ZHERONG WANG HONGXUAN HE School of Environmental Engineering Central Plains Specialty Food Engineering and Technology Research CenterKaifeng Key Laboratory of Food Composition and Quality AssessmentYellow River Conservancy Technical InstituteKaifeng475004China National Research Center for Wildlife-Borne Diseases Key Laboratory of Animal Ecology and Conservation BiologyInstitute of ZoologyChinese Academy of SciencesBeijingChina

The Escherichia coli(***)is prevailing worldwide,but the epidemiology of *** infections feature regional distribution characteristics to some ***,as a zoonotic pathogen,can be transferred from animals to humans through food chain or via contact with wounds,causing a public health *** reported the swelling of proventriculus and tracheal bleeding following the death in two broiler chickens(Gallus gallus domesticus)from Beijing,*** investigate whether a virus was involved in the infection,Madin Darby Bovine Kidney(MDCK)cells were co-cultured with supernatants of proventriculus,trachea and spleen *** avian leucosis virus was detected in the samples of proventriculus and trachea,but the avian influenza virus,the Newcastle disease virus and the avian infectious laryngotracheitis virus were not *** isolates were resistant to almost all the antimicrobial as tested except for the combinations of amoxicillin/clavulanic acid and sulfamethoxazole/*** tests demonstrated the presence of antibiotic resistance genes in these *** isolates and further research revealed a novel gene profile with the presence of CTX-M-1,gyrA,gyrB,oqxA,oqxB,parC and Sul2 antibiotic resistance genes in a strain isolated from a proventriculus *** results demonstrated that the presence of antibiotic resistant *** would not necessarily cause outbreak of large-scale ***,when the bacteria carrying new antibiotic resistance genes enter the environment,it may result in the development of more virulent strains which will potentially impact human and animal health.

关键词： Patterns E coli Poultry Genes

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Microstructure characteristics of Ni-43Ti-4Al-2Nb-2Hf alloy prepared by conventional casting and directional solidification

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China Foundry 2012年第2期9卷 101-107页

作者： Pan Liwen zheng lijing Zhou Lei Zhang Huarui Tang Xiaoxia Ma Limin Zhang Hu School of Materials Science and Engineering Beijing University of Aeronautics and AstronauticsBeijing 100191China

To further investigate the microstructure characteristic and solidification mechanism, so as to provide knowledge for the microstructure control of a NiTi-AI based high-temperature structural material, the microstructure of Ni-43Ti-4AI-2Nb-2Hf （at.%） alloy ingots prepared by conventional casting （arc-melting） and directional solidification （DS） at various drawing velocities （2 ***-＇, 18 ***-1, 30 mm-min-＇ and 60 mmmin~, respectively） was investigated by means of electron probe microanalyses. Experimental results reveal that the microstructures are composed of NiTi matrix phase,/3-Nb phase and Ti2Ni phase for samples obtained by both conventional casting and DS. Conventional casting has an equiaxial structure, while DS has a slender and acicular cellular structure which grows along the [001] orientation preferentially. Small amounts of white/3-Nb phase and black Ti2Ni phase co-exist at the grain boundaries or intercellular regions. With an increase in drawing velocity, the NiTi matrix phase is inclined to grow along （100） and （200） crystallographic planes, and the cellular arm spacing reduce gradually, but the directionality of the solidified structure weakens significantly. The homogeneous dispersion of,8-Nb phase and the decrease of Ti2Ni phase in DS samples are beneficial to improving the mechanical properties. Solidification mechanism analysis indicates that the dark grey NiTi matrix phase initially precipitates from the liquid phase, and then the divorced eutectic reaction takes place, which produces the light gray matrix phase and/^-Nb phase. Finally, the peritectic reaction happens, which generates the black Ti2Ni phase.

关键词： Ni-Ti-Al-Nb-Hf alloy conventional casting directional solidification drawing velocity microstructural characteristic solidification mechanism

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扭平凡扩张与表示维数

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数学进展 2014年第4期43卷 512-520页

作者：郑立景湖南师范大学数学与计算机科学学院长沙湖南410081 赣南师范学院数学与计算机科学学院赣州江西341000

设k是代数闭域,∧是k上基本有限维连通Koszul自入射代数.本文首先证明:如果∧满足有限生成(FG)假设,那么存在∧的k-代数自同构σ0使得关于∧-双模D∧^(σ0)的扭平凡扩张T(∧^(σ0))=∧×D∧^(σ0)亦满足FG假设.由此得到,在∧满足FG假设... 详细信息

设k是代数闭域,∧是k上基本有限维连通Koszul自入射代数.本文首先证明:如果∧满足有限生成(FG)假设,那么存在∧的k-代数自同构σ0使得关于∧-双模D∧^(σ0)的扭平凡扩张T(∧^(σ0))=∧×D∧^(σ0)亦满足FG假设.由此得到,在∧满足FG假设的条件下,(1)T(A^(σ0))的表示维数大于等于∧的复杂度加2;(2)设G是∧的k-代数自同构群Aut_k(∧)的有限子群,且其阶在∧中可逆.如果对于任意的g∈G都有σ0g=gσ0,那么斜群代数∧*G的扭平凡扩张代数T((∧*G)^(σ0))的表示维数大于等于∧的复杂度加2.

关键词：表示维数有限生成假设扭平凡扩张 Koszul自入射代数

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Phase Transformation in a β-Ti Alloy with Good Balance Between High Strength and High Fracture Toughness

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Chinese Journal of Aeronautics 2009年第5期22卷 535-539页

作者： Li Yang Wei Qiang Ma Chaoli zheng lijing Li Huanxi Ge Peng Zhao Yongqing School of Materials Science and Engineering Beijing University of Aeronautics and Astronautics Beijing 100191 China Northwest Institute for Nonferrous Metal Research Xi'an 710016 China

This article studies the phase transformation of the metastable β-Ti-A1-Mo-V-Cr-Zr alloy （Ti-1300） to disclose the morphological reason for its high strength and high fracture toughness. It has been found that its ultrahigh strength （ultimate tensile strength exceeds 1 400 MPa） owes mainly to the spheroidization of the α-phase, while the high fracture toughness （exceeds 81 MPa·m^1/2） to the special lath-shaped α-particles. Compared to the needle-shaped second α-articles, the coarser lath-shaped ones remove the stress concentration at the lath tips and consequently benefit improvement of fracture toughness. The article also describes shape evolution of the α-particles during aging thermodynamically and kinetically, and suggests an optimized aging processing to achieve an ideal balance between high strength and high toughness for this alloy.

关键词： Ti-1300 titanium alloys strength of materials fracture toughness

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Corrosion Behavior of Mg_(65)Cu_(25-x) Zn_xGd_(10)(x=0, 5) Metallic Glass

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Journal of Wuhan University of Technology(Materials Science) 2008年第5期23卷 678-682页

作者：李国强 School of Materials Science and Engineering Beijing University of Aeronautics & Astronautics

The effect of substitutional element Zn on corrosion behavior of Mg65Cu25Gd10 glass was investigated. The amorphous structure of Mg65Cu25-xZnxGd10 （x=0,5） alloys were examined by X-ray diffractometry and differential scanning calorimetry （DSC）. The dissolution rates of Mg65Cu25-xZnxGd10 （x=0, 5） metallic glasses in a 5 wt% NaCl solution with pH value of 7 were determined by a hydrogen evolution testing method. The corrosion behavior of these alloys was characterized using dipping tests with 5 wt% NaCl, in combination with electrochemical measurements and scanning electron microscopy （SEM）. Results show that the anti-corrosion ability of Mg65Cu25Gd10 alloy is significantly improved due to the addition of Zn. Possible mechanism responsible for the improvement is discussed.

关键词： Mg-based metallic glass corrosion behavior corrosion resistance dissolution rate

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Microstructure Evolution of Ti-47Al-2Cr-2Nb Alloy in the Liquid-Metal-Cooling (LMC) Directional-Solidification Process

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Journal of Wuhan University of Technology(Materials Science) 2011年第2期26卷 198-202页

作者：肖志霞张虎 School of Materials Science and Engineering Beijing University of Aeronautics and Astronautics(BUAA)

The microstructure evolution of Ti-47Al-2Cr-2Nb alloy was investigated on liquid metal cooling type directional solidified apparatus at high temperature *** analysis shows that it is solidified with primary β cells/dendrites,and then α phase is formed through peritectic *** the columnar grains grow into the steady state,the lamellar orientation inclined with the angle of 45° to the withdrawal direction is more favored than that with parallel to the withdrawal *** addition,α phase grain nucleates from β-interdendrite regions,and grows up to the dendritic *** no other α grain hinders its growth,it would occupy the whole dendrite,or it would stop at the dendritic trunk for the weakened motivating drive in the β dendritic core.

关键词： TiAl-based alloy directional solidification lamellar orientation peritectic reaction

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微量元素B在γ-TiAl基合金的应用研究进展

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稀有金属材料与工程 2010年第10期39卷 1875-1880页

作者：郑立静杨莉莉张虎 Beijing University of Aeronautics and Astronautics Beijing 100191 China

综述了微量元素B在TiAl基合金中应用的研究现状,重点阐述B对TiAl基合金组织细化的机制,并分析硼化物结构与形态的影响因素及其对TiAl基合金微观组织和力学性能的影响,对B在TiAl基合金中的进一步研究应用提出了建议。

关键词：微量元素 TiAl基合金研究进展 Boron Addition Minor Progress Research Based 结构与形态组织细化影响因素研究现状微观组织力学性能硼化物机制分析

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硼含量及冷却速度对TiAl合金十字形铸件组织的影响

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稀有金属材料与工程 2011年第9期40卷 1565-1569页

作者：杨莉莉郑立静张虎北京航空航天大学北京100191

采用真空感应磁悬浮熔炼法制备Ti-47Al-2Cr-2Nb-xB(x=0,0.15,0.8,1.5)(at%)十字形不同壁厚(2、5、10、20mm)的铸件。借助体视显微镜、扫描电子显微镜(SEM)对铸件的组织进行分析,研究硼含量和冷却速度对铸件硼化物形态、晶粒细化效果的... 详细信息

采用真空感应磁悬浮熔炼法制备Ti-47Al-2Cr-2Nb-xB(x=0,0.15,0.8,1.5)(at%)十字形不同壁厚(2、5、10、20mm)的铸件。借助体视显微镜、扫描电子显微镜(SEM)对铸件的组织进行分析,研究硼含量和冷却速度对铸件硼化物形态、晶粒细化效果的影响。结果表明:硼含量越高,冷却速度越快,细化效果越好。随着硼含量的增加,硼化物的形态从弯曲条带状逐渐转变为短棒状或片状。Ti-47Al-2Cr-2Nb-0.8B铸件硼化物尺寸随冷却速度的降低而减小,Ti-47Al-2Cr-2Nb-0.15B和Ti-47Al-2Cr-2Nb-1.5B铸件硼化物随冷却速度的变化规律不明显。

关键词： TiAl基合金冷却速度晶粒尺寸硼化物

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基于F-score和二进制灰狼优化的肿瘤基因选择方法

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南京师大学报（自然科学版） 2024年第1期47卷 111-120页

作者：穆晓霞郑李婧河南师范大学计算机与信息工程学院河南新乡453007

针对肿瘤基因数据维度高、噪声多、冗余性高的现状,结合Spearman相关系数改进F-score算法,在此基础上优化二进制灰狼算法,提出了一种基于改进F-score和二进制灰狼算法的肿瘤基因选择算法.首先,考虑特征之间的相关性,计算每个特征的F-sc... 详细信息

针对肿瘤基因数据维度高、噪声多、冗余性高的现状,结合Spearman相关系数改进F-score算法,在此基础上优化二进制灰狼算法,提出了一种基于改进F-score和二进制灰狼算法的肿瘤基因选择算法.首先,考虑特征之间的相关性,计算每个特征的F-score值和特征之间的Spearman相关系数的绝对值;然后,计算权重系数得出各个特征的权重值,依据重要性进行排序,选出初选特征子集;最后,通过收敛因子的衰减曲线和初始化方法优化二进制灰狼算法,调整全局搜索和局部搜索所占比例,增强全局搜索能力并提高局部搜索速度,有效节省时间开销,提升特征选择的分类性能和效率,得到最优特征子集.在9个肿瘤基因数据集上测试所提算法,在分类准确率和筛选特征数目两个指标上进行仿真实验,并与4种其他算法进行对比,实验结果证明所提算法表现良好,可有效降低基因数据维度,并具有较好的分类精度.

关键词：肿瘤基因 Fisher-score Spearman 相关系数二进制灰狼优化算法特征选择

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