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Industrial gases Came Across Brisk Demand

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China Chemical Reporter 2008年第15期19卷 15-16页

作者： Sun Guomin,China Industrial Gas Industry Association China Industrial Gas Industry Association

Industrial gases are the basic materials for various major industrial sectors.They are extensively used in metallurgical,petroleum,petrochemical,chemical,machinery,electronic,aviation and space-flight sectors.1 Robust... 详细信息

关键词： petrochemical aviation petroleum machinery gases P

Multimodal chemo-/magneto-/phototaxis of 3G CNT-bots to power fuel cells

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Microsystems & Nanoengineering 2020年第1期6卷 1149-1160页

作者： Shirsendu Mitra Nirmal Roy Surjendu Maity Dipankar Bandyopadhyay Department of Chemical Engineering Indian Institute of Technology GuwahatiGuwahatiAssam 781039India Centre for Nanotechnology Indian Institute of Technology GuwahatiGuwahatiAssam 781039India

We report the development of a 3G microswimmer,namely,CNT-bot,capable of undergoing acid-,alkali-,magneto-and phototaxis inside acidic or alkaline baths of peroxide fuel and/or water.The use of carboxyl-functionalised multi-walled carbon nanotubes(MWCNTs)facilitated the propulsion of CNT-bots in an alkaline-water solution by ejecting carbon-dioxide bubbles.Furthermore,doping of magnetite nanoparticles(FeONPs),ferrous ions(Fe^(2+))and titanium dioxide nanoparticles(TiONPs)induces magnetic,chemical and photonic modes of propulsion.While FeONPs stimulated magnetotaxis at a rate of up to~10 body lengths per second under the influence of a bar magnet,chemotaxis of a similar speed in a peroxide fuel was achieved by bubble-propulsion of oxygen gas originating from the Fenton reaction.In addition,the light-stimulated photo-Fenton reaction led to phototaxis of CNT-bots.A thin coating of magnesium imparted a half-faced Janus appearance to the CNT-bots,which facilitated motion in normal or acidic water media through the ejection of hydrogen gas bubbles.This chemotaxis could be transformed into pH-stimulated directional motion by establishing an acid or alkali concentration gradient across the peroxide and/or water baths.The capacity of CNT-bots to produce oxygen(hydrogen)bubbles in peroxide(acidic water)fuel was exploited to power a PEM fuel cell to generate electricity.The pure oxygen and hydrogen gases generated by CNT-bots in separate chambers were fed directly into the fuel cell in which the incessant motions of the particle facilitated the creation and release of the pure gases to achieve on-demand electricity generation.The motor could also induce dye degradation through advanced oxidation owing to the production of intermediate hydroxyl radicals during the Fenton reaction.

关键词： alkali dioxide gases

Greentelligence:Smart Manufacturing for a Greener Future

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Chinese Journal of Mechanical Engineering 2021年第6期34卷 159-164页

作者： Xingyu Li Baicun Wang Tao Peng Xun Xu Department of Mechanical Engineering University of MichiganAnn ArborMI48109USA State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou310027China Department of Mechanical Engineering The University of AucklandAucklandNew Zealand1010

1 Introduction Global climate change has grown into one of the major concerns in global industrialization and economic development.Carbon dioxide(CO_(2)),one of the six Kyoto Protocol greenhouse gases(GHGs),is the most difficult to contain due to its closeness with energy generation and consumption^([1]).With an earlier awareness of climate change,developed countries tended to displace the resource-and energy-intensive industries to other countries,thus emissions have not been reduced but relocated^([2]),which can be further magnified if production shifts to countries using carbon-intensive energy or low-energyefficient technologies.Developing countries are responsible for 63%of GHGs emissions and get hit the hardest,i.e.,78%of the cost of climate change,and predicted to rise to 87%by 2035^([3]).

关键词： Smart gases emissions

Contributions of natural systems and human activity to greenhouse gas emissions

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Advances in Climate Change Research 2018年第4期9卷 243-252页

作者： YUE Xi-Liu GAO Qing-Xian China Reinsurance (Group) Corporation Post-doctoral Workstation Beijing 100033 China Beijing Normal University Beijing 100875 China Chinese Research Academy of Environmental Sciences Beijing 100012 China

In this study, we conducted a literature review of relevant research and then statistically analyzed global greenhouse gas (GHG) emissions from natural systems, including forest fires, oceans, wetlands, permafrost, mud volcanoes, volcanoes, and earthquakes. Drawing on the Global Carbon Project (GCP) report, we also summarized the global anthropogenic GHG emissions. We then compared the global annual GHG emissions from natural systems with those generated by human activity. The results indicate that the global annual GHG emissions range approximately between 54.33 and 75.50 Gt CO2-eq, of which natural emissions account for 18.13e39.30 Gt CO2-eq, with the most likely value being approximately 29.07 Gt CO2-eq. According to the GCP report, the global anthropogenic emissions have increased from 22 Gt CO2-eq in 1990 to 36.2 Gt CO2-eq in 2016. The amounts of natural and anthropogenic GHGs emissions are roughly of the same order of magnitude. Anthropogenic emissions account for approximately 55.46% of the total global GHGs emissions (2016 value), i.e., the ratio of natural to anthropogenic emissions is approximately 0.8. In addition, the annual amount of GHGs absorbed by Earth systems (ocean and terrestrial ecosystems) ranges between approximately 14.4 Gt CO2-eq and 26.5 Gt CO2-eq, with natural system GHG emissions and sinks also having roughly the same order of magnitude. This finding indicates that the GHG emissions generated by human activity exert extra pressure on what is otherwise a self-balancing Earth system.

关键词： Greenhouse gases Natural emission Anthropogenic emission Global emission Natural system

Single-atom catalysts boosted ultrathin film sensors

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Rare Metals 2020年第10期39卷 1110-1112页

作者： Rahul Kumar Mahesh Kumar Department of Electrical Engineering Indian Institute of Technology JodhpurJodhpur 342037India

Nowadays,demand for fast and accurate detection of toxic and flammable gases is increasing for human health safety,industrial process and environmental monitoring.So,gas sensor technology has become a requisite in our daily life.Emerging nanoscience and nanotechnology propel fabrication of a gas sensor at the miniaturization level for burgeoning Internet of things applications.

关键词： film nanotechnology gases

Simulation of Helium Behaviour in Titanium Crystals Using Molecular Dynamics

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Chinese Physics Letters 2006年第7期23卷 1666-1669页

作者：汪俊侯氢孙铁英吴仲成龙兴贵吴兴春罗顺忠 Key Laboratory for Radiation Physics and Technology Institute of Nuclear Science and Technology Sichuan University Chengdu 610064 Institute of Nuclear Physics and Chemistry China Academy of Engineering Physics Mianyang 621900

The behaviour of helium in Ti crystals at 300 K has been investigated by means of the molecular dynamics. The study is focused on the influences of He-Ti interaction on the aggregation of helium atoms in the substrate. When a Born-Mayer potential is used to describe the He-Ti interaction, the He atoms are unable to cluster with each other due to the weak bridge barrier that cannot trap the helium atoms, Whereas using a He-Ti potential that is constructed by fitting the ab initio pairwise He-Ti potential, the clustering of He atoms can be observed. The results indicate that suitable He-Ti potential plays an important role in the formation of He clusters in metals. Moreover, it is noted that the shape of the formed He cluster is irregular, and the produced defect prefers to congregating on one side of the He cluster rather than spreading symmetrically around it.

关键词： CLUSTERS METALS ALLOY gases

Transmission characteristics of photonic crystal fiber gas cell used in frequency stabilized laser

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Chinese Optics Letters 2014年第8期12卷 23-27页

作者：黄崇德陈迪俊蔡海文翟荣辉陈卫标 Key Laboratory of Space Laser Communication and Detection Technology Shanghai Institute of Optics and Fine MechanicsChinese Academy of Sciences University of Chinese Academy of Sciences

We measure the transmission characteristics of hollow-core photonic crystal fiber （HC-PCF） gas cells with ferrule- and fusion-spliced configurations, and near- and far-field images of the HC-PCF are observed. Results show that the center of mass （COM） of the far-field image varies with the laser frequency and temperature, and the moving COM relates to the oscillatory transmission. Using a model of the spatial interference, we first demonstrate that mainly the modes with asymmetric phase distributions affect the COM position. The frequency stabilization performances of the lasers are compared. The fusion-spliced gas cell shows better performance than the ferrule-spliced one.

关键词： Crystal whiskers Feedback gases Nonlinear optics

Room-Temperature Inductively Coupled Plasma Etching of InP Using Cl2/N2 and Cl2/CH4/H2

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Chinese Physics Letters 2006年第4期23卷 903-906页

作者：李志伟陈美凯 Photonics Research Centre School of Electrical and Electronic Engineering Nanyang Technological University Singapore 639798 Singapore

We optimize the room-temperature etching of InP using Cl2/CH4/H2 and Cl2/N2 inductively coupled plasma reactive ions. A design of experiment is used in the optimization. The results, in terms of etch rate, surface roughness and etched profile, are presented. These Cl2-based recipes do not require substrate heating and thus can be more cost effectively and widely applied. The Cl2/CH4/H2 process is able to give a higher etch rate （about 850 nm/min） and cleaner surface with less polymer formation compared to the conventional CH4/H2 process. The Cl2/N2 process produces even higher etch rate （as high as 2μm/rain）, but rougher surface with slight sidewall undercut. The Cl2/N2 process also has no polymer formation due to the absence of methane gas. Both the processes give very good selectivity to the silicon dioxide （SiO2） etch mask. The selectivity of InP to the oxide mask （up to 55：1） for the Cl2/N2 process is one of the highest reported so far. The etched structures possess reasonably good sidewall verticality and surface quality comparable to that obtained under elevated temperature condition （〉 200℃）.

关键词： COMPOUND SEMICONDUCTORS FABRICATION SMOOTH gases CHEMISTRIES MIXTURES SIDEWALL LASERS

Stability Diagrams of a Bose-Einstein Condensate in Excited Bloch Bands

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Chinese Physics Letters 2009年第1期26卷 227-230页

作者：梁兆新胡斑比 Department of Physics Centre for Nonlinear Studies and The Beijing-Hong Kong-Singapore Joint Centre for Nonlinear and Complex (Hong Kong) Hong Kong Baptist University Kowloon Tong Hong Kong Department of Physics University of Houston Houston Texas 77204-5005 USA

Landau and dynamical instabilities o/a Bose-Einstein condensate （BEC） in the excited bands of a one-dimensional optical lattice are investigated by the Gross Pitaevskii theory. Our results show that there always exists Landau instability for a BEC in the whole region of excited bands. We also map out the dangerous zones of the dynamical instability. The experimental implications of the stability diagram are discussed.

关键词： OPTICAL LATTICES SUPERFLUID DYNAMICS gases