检索结果-南通市图书馆

Oxidation of antimony (Ⅲ) in soil by manganese (Ⅳ) oxide using X-ray absorption fine structure

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2018年第11期30卷 31-37页

作者： lei fu Katsumi Shozugawa Motoyuki Matsuo Graduate School of Arts and Sciences The University of Tokyo 3-8-1 Komaba Meguro-ku Tokyo 153-8902 Japan

The oxidation of antimony （Ⅲ） in soils was studied using X-ray absorption fine structure （XAFS） spectra. An andosol soft sample and artificial soil samples （SiO2 blended with iron （Ⅲ） hydroxide and manganese （Ⅳ） oxide） were used herein. After adding antimony （Ⅲ） oxide to all soil samples, the oxidation process was observed by recording the XAFS spectra of Sb K-edge, Fe Kedge, and Mn K-edge. The results indicated that manganese （Ⅳ） oxide played an important role in the oxidation of Sb（Ⅲ）; however iron （Ⅲ） hydroxide was not directly related to the reaction. During a 2-hr continuous Sb K-edge X-ray absorption near edge structure （XANES） measurement with an interval of I rain of one of the artificial soil samples （SiO2 ＋ MnO2 ＋ Sb2O3）, a pseudo-first-order reaction was determined with an average estimated rate of 0.52 ±0.04 hr-1. Compared to the lower oxidation rate of andosol, it is suggested that because of the low concentration of Mn（Ⅳ） in natural soils, the oxidation process of Sb（Ⅲ） might be relatively slow and require more time to convert Sb（Ⅲ） to Sb（V）.

关键词： Soil Antimony Oxidation Manganese (Ⅳ) oxide X-ray absorption fine structure (XAFS)

On pulsar-driven mass ejection in low-mass X-ray binaries

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2011年第12期11卷 1457-1468页

作者： lei fu Xiang-Dong Li Department of Astronomy Nanjing University Nanjing 210093 China Key Laboratory of Modem Astronomy and Astrophysics Ministry of Education Nanjing 210093 China

There is accumulating evidence for mass ejection in low-mass X-ray binaries （LMXBs） driven by radio pulsar activity during X-ray quiescence. We consider the condition for mass ejection by comparing the radiation pressure from a millisecond pulsar, and the gas pressure at the inner Lagrange point or at the surrounding accretion disk. We calculate the critical spin period of the pulsar below which mass ejection is allowed. Combining with the evolution of the mass transfer rate, we present constraints on the orbital periods of the systems. We show that mass ejection could happen in both wide and compact LMXBs. It may be caused by transient accretion due to thermal instability in the accretion disks in the former, and irradiation-driven mass-transfer cycles in the latter.

关键词： pulsars: general- binaries: general

Stability for Impulsive functional Differential Equations with Infinite Delays

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2010年第5期26卷 909-922页

作者： Xian Long fu lei ZHOU Department of Mathematics East China Normal University Shanghai 200241 P. R. China

In this paper, some theorems of uniform stability and uniform asymptotic stability for impulsive functional differential equations with infinite delay are proved by using Lyapunov functionals and Razumikhin techniques... 详细信息

关键词： impulsive functional equation infinite delay stability Lyapunov functional

Thickening-upward cycles in deep-marine and deep-lacustrine turbidite lobes:examples from the Clare Basin and the Ordos Basin

在线全文

学校读者我要写书评

暂无评论

Journal of Palaeogeography 2020年第2期9卷 216-231页

作者： lei-fu Zhang Da-Zhong Dong PetroChina Research Institute of Petroleum Exploration and Development Beijing 100083China School of Geological Sciences University College DublinDublin 4Ireland National Energy Shale Gas Research(Experiment)Center Langfang 065CX)7Hebei ProvinceChina CNPC Key Laboratory of Unconventional Oil and Gas Langfang 065007Hebei ProvinceChina

Deep-marine and deep-lacustrine reservoirs have been targets for conventional and unconventional oil and gas exploration and development for decades. Thickening-upward cycles in the deep-marine Carboniferous Ross Sandstone Formation outcrops in western Ireland and the deep-lacustrine Triassic Yanchang Formation outcrops in southeast Ordos Basin have been investigated and correlated in this study. Typical thickening-upward cycles consisting of, from bottom to top:(1) laminated shales/shales with interbedded siltstone beds;(2) interbedded sandstones/siltstones and mudstones;(3) structureless massive sandstones, are well recognized in these outcrops and are interpreted as turbidite lobes. A continuously prograding lobe-element model is proposed to explain the repeated stacking of thickening-upward cycles. Thickening-upward cycles developed within deep-marine and deeplacustrine environments are highly comparable in many aspects, such as sedimentary structures, sheet-like geometries and amalgamation features. A frequent and strong degree of amalgamation is developed within the massive sandstone at the top of each thickening-upward cycle, suggesting a layer-by-layer depositional *** observations and comparison with deep-marine counterparts support the occurrence of turbidity flows in the Yanchang Formation, Ordos Basin.

关键词： Thickening-upward cycle Deep-marine turbidite Deep-lacustrine turbidite Yangchang Formation Ordos Basin Kilbaha Bay

Chia Chi Wang and his research on Protozoology

在线全文

学校读者我要写书评

暂无评论

Protein & Cell 2022年第7期13卷 473-475页

作者： Ting Shi lei fu Zhejiang Normal University Jinhua 321004China

Chia Chi Wang(王家楫,1898-1976)was a famous protozoologist,the founder of protozoology and pioneer of rotif-erology in China(Fig.1).Chia Chi Wang was bom in a scholarly family in Fengxian,*** the age of six,he began to study at the Zhaowen *** the country was declining,his father advocated that scholars should learn advanced tech no logy to change the status *** father's pioneering spirit and enlightened attitude towards new things had a profound impact on Chia Chi Wang's life.

关键词：王家楫 Chi father

Fern botanist Ren-Chang Ching and his taxonomic system

在线全文

学校读者我要写书评

暂无评论

Protein & Cell 2021年第12期12卷 903-905页

作者： Xunfeng Xu lei fu Zhejiang Normal University Jinhua 321004China

Ren-Chang Ching(秦仁昌,1898-1986)is a famous botanist in China(Fig.1).He is known as the father of Chinese pteridology,having done extensive research on *** Ren-Chang Ching System established by him has made great con... 详细信息

关键词： has taxonomy Ching

Space-confined growth of metal halide perovskite crystal films

在线全文

学校读者我要写书评

暂无评论

Nano Research 2021年第6期14卷 1609-1624页

作者： Linyi Li Jinxin Liu Mengqi Zeng lei fu Country College of Chemistry and Molecular Sciences Wuhan UniversityWuhan430072China

Metal halide perovskites,as a new generation of optoelectronic materials,have attracted a great deal of interest due to their remarkable intrinsic *** to the excellent optoelectronic properties,the perovskite crystals are widely used in lasers,photodetectors,X-ray detectors and solar *** the device performance and fabrication requirements,proper thickness of the crystal is required to avoid carrier loss and simultaneously ensure sufficient light absorption,which can realize the full potential of its excellent carrier transport ***,the fabrication of perovskite crystal in a thin film with an adjustable thickness is highly *** space-confined method has been demonstrated to be an effective way of preparing perovskite with controlled *** this method,the thickness of perovskite can be regulated flexibly in a geometric confined ***,the size,quality and architecture of perovskite crystal films are also major concerns for practical photoelectric devices,which can also be optimized by the space-confined method owing to its good adaptability towards various modified *** a word,the space-confined method is not only a simple and conventional way to adjust the thickness of perovskite crystal films,but also provides a platform to optimize their size,quality and architecture through applying appropriate strategies to the confined ***,we review the space-confined growth of perovskite crystal ***,various modified strategies based on the space-confined method applied to the optimization of thickness,size,quality and architecture are *** the stability investigating and component regulating of perovskite crystal films would be also ***,the correlation between the perovskite thickness and the device performance is ***,several key challenges and proposed solutions of perovskite thin films based on the space-confined method are discussed.

关键词： space confinement metal halide perovskite thickness adjustment controllable preparation

Towards Energy Efficient Shape Rolling:Roll Pass Optimal Design and Case Studies

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

Chinese Journal of Mechanical Engineering 2019年第3期32卷 78-88页

作者： Kan Huang Bin Huang lei fu Kazem Abhary School of Civil Engineering Changsha University of Science and TechnologyChangsha 410114China School of Engineering University of South AustraliaAdelaideSouth Australia 5095Australia

Shape rolling is widely employed in the production of long workpieces with appropriate cross-section profiles for other industrial applications. In the development of shape rolling systems, roll pass design (RPD) plays an essential role on the quality control of products, service life of rolls, productivity of rolling systems, as well as energy consumption of rolling operations. This study attempts to establish a generic strategy based on hybrid modeling and an improved genetic algorithm, to support the optimizations of RPD and shape rolling operations at a systematic perspective. Objectives include improving the quality and efficiency of RPD, reducing energy consumption of shape rolling, as well as releasing the demands on costly trails and expert knowledge in RPD. Hybrid modeling based on cross-disciplinary knowledge is developed to overcome the limitations of isolated single-disciplinary models. And conventional genetic algorithm is improved for the implementation of optimal design. Targeting to integrate empirical data and published reliable solutions into optimizations, a parameters estimation method is proposed to transfer the initially misaligned models into a uniform pattern. A tool based on the Matlab platform is developed to demonstrate the optimal design operations, with case studies involved to validate the proposed methodology.

关键词： Roll pass optimal design Hybrid modelling Genetic algorithm Parameters estimation

Multivariate analysis of surface water quality in the Three Gorges area of China and implications for water management

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2011年第9期23卷 1460-1471页

作者： Jian Zhao Guo fu Kun lei Yanwu Li Chinese Research Academy of Environmental Sciences Beijing 100012 China.

Multivariate statistical techniques,cluster analysis,non-parametric tests,and factor analysis were applied to analyze a water quality dataset including 13 parameters at 37 sites of the Three Gorges area,China,from 2003–2008 to investigate spatio-temporal variations and identify potential pollution *** cluster analysis,the twelve months of the year were classified into three periods of lowflow （LF）,normal-flow （NF）,and high-flow （HF）;and the 37 monitoring sites were divided into low pollution （LP）,moderate pollution （MP）,and high pollution （HP）.Dissolved oxygen （DO）,potassium permanganate index （COD Mn ）,and ammonia-nitrogen （NH 4 ＋-N） were identified as significant variables affecting temporal and spatial variations by non-parametric *** analysis identified that the major pollutants in the HP region were organic matters and nutrients during NF,heavy metals during LF,and petroleum during *** the MP region,the identified pollutants primarily included organic matter and heavy metals year-around,while in the LP region,organic pollution was significant during both NF and HF,and nutrient and heavy metal levels were high during both LF and *** main sources of pollution came from domestic wastewater and agricultural activities and runoff;however,they contributed differently to each region in regards to pollution *** the HP region,inputs from wastewater treatment plants were significant;but for MP and LP regions,water pollution was more likely from the combined effects of agriculture,domestic wastewater,and chemical *** results provide fundamental information for developing better water pollution control strategies for the Three Gorges area.

关键词： water quality spatial variations seasonal variations multivariate statistical techniques the Three Gorges