检索结果-南通市图书馆

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

马尾藻海藻多糖生物活性研究新进展

现代农业科技 2019年第12期 211-214,218页

作者：周乾云欧阳月红李勇许诺吴明江姜潮温州大学生命与环境科学学院

近年来的研究表明,马尾藻中富含多种新型生物活性化合物,如海藻多酚、海藻多糖及多种硫酸多糖衍生物。在分离出的生物活性成分中,海藻多糖因其具有良好的保健作用和药用效果而备受关注。同时,有大量研究已经证明,马尾藻海藻多糖对人类... 详细信息

近年来的研究表明,马尾藻中富含多种新型生物活性化合物,如海藻多酚、海藻多糖及多种硫酸多糖衍生物。在分离出的生物活性成分中,海藻多糖因其具有良好的保健作用和药用效果而备受关注。同时,有大量研究已经证明,马尾藻海藻多糖对人类疾病的预防以及恢复具有积极效果。因此,本文对近年来马尾藻海藻多糖的抗凝血、抗氧化、抗肿瘤、抗血管生成和抗炎症活性的最新进展进行了综述,以期能助推马尾藻海藻多糖的研究,并且协助填补理论研究与工业应用之间的知识鸿沟。

关键词：马尾藻海藻多糖抗肿瘤抗凝血抗氧化

Model test of the group piles foundation of a high-speed railway bridge in mined-out area

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2016年第4期10卷 488-498页

作者： Xin LIANG Qian-gong CHENG Jiu-jiang wu Jian-ming CHEN Faculty of Geoseienees and Environmental Engineering Southwest Jiaotong University Chengdu 611756 China Faculty of Civil Engineering Guangxi University of Science and Technology Liuzhou 545006 China

The research on the mechanism of pile-soil-cap-goaf interaction and settlement of high-speed railway bridge located in mined-out area is still relatively rare. By taking the pile group of Guanshandi bridge foundation in Hefei- Fuzhou high-speed railway as the prototype, a model test is carried out. According to the similarity theory, the similar constant is derived and the similar model material is determined. Meanwhile, three types of data including the bearing behavior of piles, and the settlement law, and soil among piles are investigated. It can be found that： the influence of goaf on the bearing capacity of pile is inversely to the loading degree, the larger of loading degree, the smaller impact of goaf on the bearing capacity. There is no negative side friction can been found in pile body and the degree of downward tendency for the barycenter of side friction layout is obvious for piles in goaf. Although the bearing ratio of soil resistance under cap is relatively large, the cap effect is suggested be ignored considering the characteristic of goaf. There is a maximum critical value for the uneven settlement of pile group in goaf, and when the value is reached, the uneven settlement stop growing anymore. In addition, the formula for calculating bearing capacity and settlement of pile group in goaf based on test results, theory analysis and related standard is established.

关键词： high-speed railway mined-out areas goaf group piles foundation physical model test bearing capacity,settlement

Sedimentary paleoenvironment and its control on organic matter enrichment in the Mesoproterozoic hydrocarbon source rocks in the Ordos Basin,southern margin of the North China Craton

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2024年第4期21卷 2257-2272页

作者： Zhi-Chen wu Ju-Ye Shi Tai-Liang Fan ming jiang School of Energy Resources China University of Geosciences(Beijing)Beijing100083China Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Enrichment Mechanism Ministry of EducationChina University of Geosciences(Beijing)Beijing100083China

The black shale of the Mesoproterozoic Cuizhuang Formation in the Changcheng System in Yongji city,North China Craton,is a potential source *** the organic matter enrichment mechanism is crucial for evaluating source rock resources and understanding oil and gas accumulation *** this study,we evaluated the sedimentary paleoenvironment and organic matter enrichment mechanisms of shale using thin section observations,mineral composition analysis,organic geochemistry,and elemental *** found significant differences in the sedimentary paleoenvironment and organic matter enrichment mechanisms between the lower Cuizhuang Formation and the Beidajian Formation *** Cuizhuang Formation was deposited in a late-stage,restricted basin environment during the rift phase,and elemental and geochemical indicators showed that the Cuizhuang Formation was in a suboxic-anoxic water environment,that was influenced by a warm and humid paleoclimate and submarine hydrothermal activities,which promoted the accumulation of organic ***,the enrichment of organic matter in the Cuizhuang Formation was mainly controlled by redox *** formation of suboxic-anoxic water environments may be closely related to the warm and humid paleoclimate and submarine hydrothermal *** conditions promote continental weathering and increase marine productivity,thereby consuming oxygen in the bottom ***,acidic hydrothermal activity also helps to establish an anoxic *** results reveal the effects controlling various coupled mechanisms dominated by redox conditions,which may explain the development of source rocks in the Cuizhuang Formation.

关键词： Cuizhuang formation Paleoproterozoic source rocks Marine productivity Paleoenvironments Submarine hydrothermal activity Organic matter enrichment

Orientation Dependence of the Micro-Pillar Compression Strength in an Electron Beam Melted Ti-6Al-4V Alloy

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2021年第4期34卷 476-484页

作者： Jinsen Tian jiang Ma ming Yan Zhuo Chen Jun Shen Jing wu College of Mechatronics and Control Engineering Shenzhen UniversityShenzhen518060China Department of Materials Science and Engineering and Shenzhen Key Laboratory for Additive Manufacturing of High-Performance Materials Southern University of Science and TechnologyShenzhen518055China Aerospace Hiwing(Harbin)Titanium Industrial Co. Ltd.Harbin150028China Cryo-EM Center Southern University of Science and TechnologyShenzhen518055China

An α/β two-phase Ti-6Al-4V alloy was fabricated by electron beam melting to obtain a basketweave *** orientation dependence of the mechanical properties of Ti-6Al-4 V alloy was studied by micro-pillar compression and post-mortem transmission electron microscopy *** results indicate that different grains have different mechanical responses,and the possible attributions were *** the orientation effect,due to the limited volumes of micropillars,the size of the a phases,dispersion of the β phases,and the presence of the free dislocation path also affect the mechanical properties of the micropillars to a large *** no direct link was discovered between the mechanical properties and the parent β orientations,this work provided a promising method to further study the anisotropic mechanical behavior in Ti-6Al-4V alloy.

关键词： Electron beam melting(EBM) Ti-6Al-4V Micro-pillar compression Orientation dependence Mechanical properties

Geometric error measuring,modeling,and compensation for CNC machine tools:A review

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第2期37卷 163-198页

作者： Zhao ZHANG Feng jiang ming LUO Baohai wu Dinghua ZHANG Kai TANG Engineering Research Center of Advanced Manufacturing Technology for Aero Engine(Northwestern Polytechnical University) Ministry of EducationXi’an 710072China Key Laboratory of High Performance Manufacturing for Aero Engine(Northwestern Polytechnical University) Ministry of Industry and Information TechnologyXi’an 710072China Department of Mechanical and Aerospace Engineering Hong Kong University of Science and TechnologyHong KongChina

Geometric error,mainly due to imperfect geometry and dimensions of machine components,is one of the major error sources of machine *** that geometric error has significant effects on the machining quality of manufactured parts,it has been a popular topic for academic and industrial research for many years.A great deal of research work has been carried out since the 1970s for solving the problem and improving the machining *** have studied how to measure,detect,model,identify,reduce,and compensate the geometric *** paper presents a thorough review of the latest research activities and gives an overview of the state of the art in understanding changes in machine tool performance due to geometric *** advances in measuring the geometrical errors of machine tools are summarized,and different kinds of error identification methods of translational axes and rotation axes are illustrated ***,volumetric geometric error modeling,tracing,and compensation techniques for five-axis machine tools are emphatically ***,research challenges in order to improve the volumetric accuracy of machine tools are also highlighted.

关键词： Error compensation Error identification Error measurement Error modeling Geometric error Machine tools

Trajectory modeling revealed a southwest-northeast migration corridor for fall armyworm Spodoptera frugiperda(Lepidoptera:Noctuidae)emerging from the North China Plain

在线全文

学校读者我要写书评

暂无评论

Insect Science 2021年第3期28卷 649-661页

作者： Qiu-Lin wu Yu-Ying jiang Jie Liu Gao Hu Kong-ming wu State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing100193China National Agro-Tech Extension and Service Centre Beijing100125China Department of Entomology Nanjing Agricultural UniversityNanjing210095China

The fall armyworm Spodoptera frugiperda,an invasive insect pest native to the Americas,has established populations throughout eastern *** North China Plain一a key corn-producing area in East China with a unique topography一was invaded by fall armyworm in 2019 and is seriously threatened by this migratory ***,the spatiotemporal extent of the migratory movements of fall armyworm from the North China Plain remains poorly *** an air transport-based trajectory modeling approach that incorporates flight behavior,we simulated the potential nocturnal migration trajectories of fall armyworm from the North China Plain based on historical meteorological data from June to October of 2015-2019,and examined the night-time atmospheric conditions associated with their possible *** emigration patterns showed monthly variation in the main landing area and common migration *** displacement of newly emerged moths from the North China Plain was concentrated in the Northeast China Plain(including Liaoning,Jilin and Heilongjiang provinces)before late summer,after which they were most likely to undertake return flights to the south(especially into Hubei,Anhui and Hunan provinces).This southwest-northeast aerial migration corridor follows the topography of East China and is affected by the East Asian *** topographic-atmospheric conditions have resulted in the North China Plain becoming a key stopover for fall armyworm populations engaging in multigenerational long-distance migration across East *** findings contribute to our knowledge of fall army-worm migration and will aid in the implementation of management and control strategies against this highly migratory agricultural pest.

关键词： atmospheric conditions fall armyworm invasive pest migration pattern North China Plain potential redistribution

Comparative study of microbial community structure in different filter media of constructed wetland

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2010年第1期22卷 127-133页

作者： ming Li Qiaohong Zhou Min Tao Ying Wang Lijuan jiang Zhenbin wu State Key Laboratory of Freshwater Ecology and Biotechnology Institute of Hydrobiology Chinese Academy of Sciences Wuhan 430072 China Graduate University of Chinese Academy of Sciences Beijing 100039 China School of Resource & Environmental Engineering Wuhan University of Technology Wuhan 430070 China

Comparisons of microbial community structure, in eight filter media of zeolites, anthracite, shale, vermiculite, ceramic filter media, gravel, steel slag and bio-ceramic, were undertaken by analyzing the phospholipid fatty acid （PLFA） composition. A total of 20 fatty acids in the range of C18to C20 were determined but only 13 PLFAs were detected in steel slag. They consist of saturated fatty acids, branched fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids. The variation of fatty acids was revealed in the relative proportions of these fatty acids in different media. The aerobic prokaryotes were the predominant group in all media. The PLFA composition showed significant differences among the eight different media by Tukey＇s honestly test. It was found that steel slag was significantly different in the microbial community as compared to other filter media, probably due to its alkaline effluent. Steel slag alone is probably not a good choice of substratum in constructed wetlands. The principle components analysis （PCA） showed that zeolites, bio-ceramic, shale and vermiculite had a similar microbial community structure while steel slag and ceramic filter media were distinct from other media.

关键词： microbial community structure phospholipid filter media biomarkers constructed wetland steel slag

Transfer and Transformation of Soil Iron and Implications for Hydrogeomorpholocial Changes in Naoli River Catchment, Sanjiang Plain, Northeast China

在线全文

学校读者我要写书评

暂无评论

Chinese Geographical Science 2011年第2期21卷 149-158页

作者： jiang ming LU Xianguo WANG Hongqing ZOU Yuanchun wu Haitao Key Laboratory of Wetland Ecology and Environment Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Changchun 130012 China National Wetland Research Center USGS Lafayette Louisiana 70506 USA

Wetland soils are characterized by alternating redox process due to the fluctuation of waterlogged conditions. Iron is an important redox substance, and its transfer and transformation in the wetland ecosystem could be an effective indicator for the environment changes. In this paper, we selected the Naoli River catchment in the Sanjiang Plain, Northeast China as the study area to analyze the dynamics of transfer and transformation of soil iron, and the relationship between iron content change and environmental factors. The results show that the total and crystalline iron contents reach the peak in the depth of 60 cm in soil profile, while the amorphous iron content is higher in the topsoil. In the upper reaches, from the low to high landscape positions, the total and crystalline iron contents decrease from 62.98 g/kg to 41.61 g/kg, 22.82 g/kg to 10.53 g/kg respectively, while the amorphous iron content increases from 2.42 g/kg to 8.88 g/kg. Amorphous iron content has positive correlation with organic matter and soil water contents, while negative correlation with pH. Moreover, both the crystalline and amorphous iron contents present no correlation with total iron content, indicating that environmental factors play a more important role in the transfer and transformation of iron other than the content of the total iron. Different redoximorphic features were found along the soil profile due to the transfer and transformation of iron. E and B horizons of wetland soil in the study area have a matrix Chroma 2 or less, and all the soil types can meet the criteria of American hydric soil indicators except albic soil.

关键词： wetland soil landscape position hydrogeomorpholocial condition redoximorphic feature iron

Synthesis,Crystal Structure and Properties of A Triphenyltin Schiff Complex with Salicylidene-2-aminophenol

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2018年第2期37卷 270-276页

作者： ZHANG Fu-Xing wu Qian KUANG Dai-Zhi YU jiang-Xi jiang wu-Jiu ZHU Xiao-ming Department of Chemistry and Material Science Hengyang Normal UniversityKey Laboratory of Functional Metal-organic Compounds of Hunan Province Key Laboratory of Functional Organometallic Materials of Hengyang Normal University College of Hunan ProvinceHengyangHunan 421008China

The triphenyltin complex with salicylidene-2-aminophenol （C31H24NO2Sn, 1） has been synthesized and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, and X-ray single-crystal diffraction. The complex crystallizes in monoclinic system, P21/c space group with a = 1.09515（8）, b = 1.17739（8）, c = 2.29075（14） nm, β = 117.070（4）°, V = 2.6302（3） nm3, Z = 4, Dc = 1.417 g/cm3, ？ = 0.999 mm–1, F（000） = 1123, R = 0.0472 and wR = 0.1169. X-ray single-crystal diffraction showed that 1 demonstrates a one-dimensional chain structure. The quantum chemical calculation of 1 has been investigated. Complex 1 emits fluo- rescence at 558 nm and exhibits certain inhibitory activity against NCI-H460, A549 and MCF-7.

关键词： triphenyltin complex with salicylidene-2-aminophenol organotin synthesis,crystal structure vitro anticancer activity