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Understanding the Interactions between Climate Change,Landscape Evolution,Surface Processes and Tectonics in the Earth System:What Can the Studies of Chinese Deserts Contribute?

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Acta Geologica Sinica(English Edition) 2016年第4期90卷 1444-1454页

作者： YANG Xiaoping Bernhard EITEL Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of Sciences Geographisches Institut Universit?t Heidelberg

Due to large deserts on Earth surface a thorough understanding of climate change, landscape evolution and geomorphological processes having occurred in deserts is crucial for Earth System Science. The landscapes in deserts are, however, diverse and different over the globe with regard to their geomorphological nature, human activities and geological histories. In the last decades a great number of efforts have been put to the investigation of the initial timing of the occurrence of arid climate, e. g. in northwestern China. Silty sediments in the downwind directions have been used to deduce the histories of deserts. In general, there is a lack of knowledge about processes and landscapes in Chinese drylands between the initial Miocene silt sedimentation at desert margins and the late Quaternary multiple occurrences of wetter climate with assumed large lakes in many of the deserts in northern China. The geomorphological concept of three primary triggering factors, i.e., the sediment supply, sediment availability and transport capacity of wind, and additionally the underground geology need to be fully considered for a better understanding of the environmental histories of sand seas which should not be viewed as equivalent for deserts because sand seas cover between 〈 1% and ca. 45% of the desert areas in various continents dependent on a complex interaction between various processes of both exogenous and endogenous origins.

关键词： desert sand sea earth surface process global change Quaternary geology geomorphology

Benefits Realization Management of Computer Vision in Construction:A Missed,Yet Not Lost,Opportunity

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Engineering 2023年第8期27卷 11-13页

作者： Peter E.D.Love Jane Matthews Weili Fang Hanbin Luo School of Civil and Mechanical Engineering Curtin UniversityPerthWA 6845Australia b School of Architecture and Built Environment Deakin University Geelong Waterfront CampusGeelongVIC 3220Australia Department of Civil and Building Systems Technische Universität BerlinBerlin 13156Germany National Center of Technology Innovation for Digital Construction Huazhong University of Science and TechnologyWuhan 430074China School of Civil Engineering and Mechanics Huazhong University of Science and TechnologyWuhan 430074China

*** While the applications of computer visions are varied in construction,research has tended to focus on measuring the accuracy of object detectors such as faster region-based-convolution neural networks(Faster R-CNN)and single shot detector algorithms(SDD)[1].Limited,if any,attention has focused on determining the benefits of such technology in construction beyond the claims that it can help detect problems quickly and *** this point are the numerous review papers that have frequented the literature[2,3].

关键词： faster Management benefits

Manufacturing size effect on the structural and mechanical properties of additively manufactured Ti-6Al-4V microbeams

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Journal of Materials Science & Technology 2023年第18期149卷 18-30页

作者： Kaiyang Yin Bo Cao Juraj Todt Florian Gutmann Hasan Furkan Tunçay Antonina Roth Frank Fischer Nadira Grübel Aron Pfaff Georg C.Ganzenmüller Jozef Keckes Stefan Hiermaier Christoph Eberl Department of Microsystems Engineering University of FreiburgFreiburgGermany Cluster of Excellence livMatS@FIT-Freiburg Center for Interactive Materials and Bioinspired Technologies University of FreiburgFreiburgGermany Chair of Materials Physics Montanuniversität LeobenLeobenAustria INATECH University of FreiburgFreiburgGermany Fraunhofer Ernst-Mach Institut EMIFreiburgGermany Fraunhofer IWM FreiburgGermany

The size effect of Ti-6Al-4V submillimeter structures manufactured by selective laser melting,which is critical for metallic mechanical metamaterials of unique mechanical properties,for example,nega-tive Poisson’s ratio and ultrahigh modulus,which show promise in biomedical,environmental,energy-related applications,has not been systematically *** here are the quantification of the porosities by X-ray microtomography scans,texture analysis,and mechanical characterization of the addi-tively manufactured Ti-6Al-4V *** found linearly decreasing porosities,increasing mechan-ical properties,and increasing texture in the microbeam with increasing diameter from 250 to 500μ*** variation of microstructure in microbeams of different diameters and along the sample height,result-ing from the printing parameters and the thermal conditions,leads to the discrepancy between the be-havior observed in experiments and finite element *** results provide the structure-property-processing correlation to improve the manufacturing and prediction of the mechanical behavior of metal-lic mechanical metamaterials.

关键词： Selected laser melting Porosity Texture Epitaxial growth Finite element modeling Metallic mechanical metamaterials

Precision Grinding of Reaction Bonded Silicon Carbide Using Coarse Grain Size Diamond Wheels

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Chinese Journal of Mechanical Engineering 2010年第3期23卷 269-275页

作者： ZHAO Qingliang CHEN Junyun BRINKSMEIER E Centre for Precision Engineering Harbin Institute of Technology Harbin 150001 China Laboratory for Precision Machining University of Bremen Bremen D-28359 Germany

Reaction bonded SiC（RBSiC） is attractive for optical application because of its favorable properties and low fabrication cost. However, the difficultness and cost involved in RBSiC grinding limit its application. The investigation on high efficient and low-cost machining with good grinding quality is desired. Generally, high efficient machining for RBSiC is realized by using coarse grain size grinding wheels, but serious grinding damage is inevitable. In this paper, monolayer nickel electroplated coarse grain size diamond grinding wheels with grain sizes of 46 μm, 91 μm, and 151 μm were applied to the grinding of RBSiC. An electrolytic in-process dressing（ELID） assisted conditioning technique was first developed by using cup shape copper bonded conditioning wheels with grain sizes of 15 μm and 91 μm to generate the conditioned coarse grain size wheels with minimized wheel run-out error within 2 μm, constant wheel peripheral envelop as well as top-flattened diamond grains. Then, the grinding experiments on RBSiC were carried out to investigate the grinding performance and material removal mechanism. The experimental results indicate that the developed conditioning technique is applicable and feasible to condition the coarse grain size diamond wheels under optimal conditioning parameters, and the material removal mechanism involved in RBSiC grinding is the combination of brittle fracture and ductile deformation to generate smooth ground surface. This research is significant for the high efficient and low-cost precision grinding of RBSiC with good ground surface quality.

关键词： precision grinding SiC coarse grain size diamond wheel ELID assisted conditioning material removal mechanism

Flow of a micropolar fluid in a micro-channel under the action of an alternating electric field: Estimates of flow in bio-fluidic devices

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Journal of Hydrodynamics 2015年第3期27卷 350-358页

作者： MISRA J.C. CHANDRA S. HERWIG H. Centre for Healthcare Science and Technology Indian Institute of Engineering Science and Technology Department of Physics Sabang S. K. Mahavidyalaya Vidyasagar University Institute of Thermo-Fluid Dynamics Technische Universitat Hamburg-Harburg

The paper is devoted to a study of the electro-osmotic flow of a micropolar bio-fluid, when the flow takes place between two plates that are in a state of periodic vibrations. Considering blood as a micropolar fluid, it is found that the amplitude of oscillation of the microparticles of blood increases when the micropolar effect is pronounced more and more and that a rise in DebyeHtickel parameter enhances both the velocity and microrotation gradient. The results provide guidelines for the improvement of design of bio-sensing and micro-fluidic devices. The study leads to the conclusion that electrical double layers formed in the vicinity of the wall can significantly alter the flow dynamics of physiological fluids in micro-bio-fluidic devices.

关键词： microrotation Electro-osmotic flow Debye-Hiickel parameter micropolar fluid

Geochemical baselines of major,minor and trace elements in the tropical sediments of the Terengganu River basin,Malaysia

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International Journal of Sediment Research 2010年第4期25卷 340-354页

作者： Khawar SULTAN Noor Azhar SHAZILI Department of Hydrology University of Bayreuth 95440 Bayreuth Germany Institute of Oceanography University Malaysia Terengganu Mengabang Telipot 21030 Kuala Terengganu Malaysia

The geochemical baselines and distribution of 31 elements (Al, Fe, K, Na, Mg, Ca, Mn, Ba, Cr, Zr, Ni, Sr, Zn, Y, Li, Cu, Mo, Nb, Th, Co, Ga, W, Ta, Be, Ti, Ge, Se, Bi, Te, Sc and Re) and physico-chemical parameters of the tropical surface sediments of the Terengganu River basin, Malaysia, are reported. Sediments are sandy loam to sand in texture consisting of mostly quartz, low organic matter content (average-2.68%), low CEC (average-2.02 cmol(+)/kg) and mildly acidic pH1:5 (average-5.91). Concentrations of Mn, Fe, Ba, Cr, Ni, Cu, Mo and Se were measured to be above the environmental sediment quality criteria at various locations. Lake sediments registered significantly higher Al, Fe, Ti, Mg, Ca, Mn, Te and Sc concentrations as compared to the river sediments. Most of the elements investigated showed an association with silt size fraction (2-63 μm). Among the investigated metals, Mo and Fe concentrations showed an increasing (>5-fold) and decreasing (>3-fold) trend, respectively, along the river path from the upstream to the downstream depending on the stream pH-redox conditions. The enrichment factor values (EF >5) of Cr, Ni, Mo and Se indicated enrichment from anthropogenic activities. Alkali and alkali earth metals registered a significant depletion (EF values 1,000 mg/kg) indicating contamination of sediments. This work presents the geochemical baselines of the tropical sediments as industrial development and urbanization along the north east coast of Peninsular Malaysia are advancing rapidly.

关键词： Tropical Sediment Environment Elements Geochemistry Malaysia

Recent Advances in Self-supported Layered Double Hydroxides for Oxygen Evolution Reaction

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Research 2020年第1期2020卷 635-651页

作者： Libo Wu Luo Yu Xin Xiao Fanghao Zhang Shaowei Song Shuo Chen Zhifeng Ren Department of Physics and Texas Center for Superconductivity(TcSUH) University of HoustonHoustonTX 77204USA Materials Science and Engineering Program University of HoustonHoustonTX 77204USA College of Physical Science and Technology Central China Normal UniversityWuhan 430079China Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan 430074China Department of Chemistry University of HoustonHoustonTexas 77204USA

Electrochemical water splitting driven by clean and sustainable energy sources to produce hydrogen is an efficient and environmentally friendly energy conversion *** splitting involves hydrogen evolution reaction(HER)and oxygen evolution reaction(OER),in which OER is the limiting factor and has attracted extensive research interest in the past few *** noble-metal-based OER electrocatalysts like IrO_(2) and RuO_(2) suffer from the limitations of high cost and scarce *** innovative alternative nonnoble metal electrocatalysts with high catalytic activity and long-term durability to boost the OER process remains a significant *** all of the candidates for OER catalysis,selfsupported layered double hydroxides(LDHs)have emerged as one of the most promising types of electrocatalysts due to their unique layered structures and high electrocatalytic *** this review,we summarize the recent progress on self-supported LDHs and highlight their electrochemical catalytic ***,synthesis methods,structural and compositional parameters,and influential factors for optimizing OER performance are discussed in ***,the remaining challenges facing the development of self-supported LDHs are discussed and perspectives on their potential for use in industrial hydrogen production through water splitting are provided to suggest future research directions.

关键词： splitting layered Oxygen

Absorption Enhancement of Ultrathin Crystalline Silicon Solar Cells with Dielectric Si3N4 Nanostructures

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Communications in Theoretical Physics 2019年第11期71卷 1346-1352页

作者： Xin-Yu Tan Can Deng Yi-Teng Tu Li Guan China Three Gorges University College of Materials and Chemical EngineeringKey Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion MaterialsYichang 443002China Lei Sun Department of Physics Science and Technology Hebei UniversityBaoding 071000China College of Elec trical Engineering&New Energy Hubei Provincial Collaborative Innovation Center for New Energy MicrogridYichang 443002China

A design of ultrathin crystalline silicon solar cell with Si3 N4 circular truncated cone holes(CTCs)arrays on the top is *** this article,we perform an optical simulation of the *** finite-difference time-domain method is used to calculate the optical absorption of different periods,radius of top and bottom circles and depth of Si3 N4 *** short-circuit current density generated by the optimized cells(30.17 mA/cm^2)is 32.44%more than the value gained by control group(with flat Si3 N4).Then adding a layer of back silver to allow us to better analyze optical ***,we simulate the optimization of the same configuration of different silicon thicknesses andfind that our structure does enhance the light *** work uses a combined path towards achieving higher photocurrent ultrathin crystalline silicon solar cells by constructing the texture of anti-reflection coating.

关键词： photovoltaic silicon diffraction gratings antireflection coatings

Adaptive backstepping control and synchronization of a modified and chaotic Van der Pol-Duffing oscillator

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控制理论与应用（英文版） 2011年第2期9卷 273-277页

作者： U.E.VINCENT R.K.ODUNAIKE J.A.LAOYE A.A.GBINDINNINUOLA Department of Physics Olabisi Onabanjo University Institute of Theoretical Physics Technical University of Clausthal Department of Physics University of Ibadan

In this paper,we propose a backstepping approach for the synchronization and control of modified Van-der Pol Duffing oscillator *** method is such that one controller function that depends essentially on available circuit parameters that is sufficient to drive the two coupled circuits to a synchronized state as well achieve the global stabilization of the system to its regular *** simulations are given to demonstrate the effectiveness of the technique.

关键词： Chaos Synchronization Back-stepping Van der Pol-Duffing oscillator