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Cosmology with Two Compactification Scales

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Chinese Physics Letters 2000年第4期17卷 310-312页

作者： A.G.Agnese M.la Camera Dipartimento di Fisica delPUniversita di Genova Istituto Nazionale di Fisica NucleareSezione di Genova Via Dodecaneso 3316146 GenovaItaly

We consider a(4+d)-dimensional spacetime broken up into a(4-n)-dimensional Minkowski spacetime(where n goes from 1 to 3)and a compact(n+d)-dimensional *** the present time the n compactification radii are of the order... 详细信息

关键词： manifold. length. Minkowski

All-Ti3C2TA:MXene Based Flexible On-chip Microsupercapacitor Array

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Chemical Research in Chinese Universities 2020年第4期36卷 694-698页

作者： LI la CHEN Di SHEN Guozhen State Key laboratory for Superlattices and Microstructures Institute of SemiconductorsChinese Academy of Sciences&Center of Materials Science and Optoelectronic EngineeringUniversity of Chinese Academy of SciencesBeijing 100083P.R.China School of Mathematics and Physics University of Science and Technology'BeijingBeijing 100083P.R.China

Flexible on-chip microsupercapacitors(MSCs)are highly desired for integrated wearable or portable elec-tromics due to their advantages of small size,high power density,easy integration,long lifespan,high security,and *** output voltage of MSCs can be improved by designing MSC arrays,which could further expand their application *** this work,we proposed a facile laser direct cutting method to prepare an on-chip flexible MSC array using TiC,T,MXene as both current collector and electrode *** designed MSC in PVAH2SO4 all-solid-state gel electrolvte exhibits a large volume/areal capacitance of 770.72 F/cm^3(46.24 mF/cm^2)at a scan rate of 20 mV/s,a high energy density of 68.51 mWh/cm^3 at a power density of 6.16 W/cm^3,excellent cveling stability with capacitance retention of 98.50%after 10000 charge/discharge *** MSC also shows superior flexibility and stabilitv even after repetition of charge/discharge cvcles under the convex and concave bending *** *** assembled MSC array(4 in series)provides a high voltage of 3.2 V,which could easily power a purple light-emitting diode more than 10 min,demonstrating its potential application in integrated portable/wearable devices.

关键词： Ti3C2Tx MXene Microsupercapacitor laser cutting Flexible energy storage

GSTARS computer models and their applications, Part Ⅱ: Applications

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International Journal of Sediment Research 2008年第4期23卷 299-315页

作者： Francisco J.M.SIM■es Chih Ted YANG Research Hydrologist US Geological Survey Geomorphology and Sediment Transport Laboratory4620 Technology Drive Suite 400 Golden CO 80403 USA Borland Prof. of Water Resources and Director of Hydroscience and Training Center Department of Civil and Environmental Engineering Colorado State UniversityFort Collins CO 80523-1372 USA

In part 1 of this two-paper series, a brief summary of the basic concepts and theories used in developing the Generalized Stream Tube model for Alluvial River Simulation (GSTARS) computer models was presented. Part 2 provides examples that illustrate some of the capabilities of the GSTARS models and how they can be applied to solve a wide range of river and reservoir sedimentation problems. laboratory and field case studies are used and the examples show representative applications of the earlier and of the more recent versions of GSTARS. Some of the more recent capabilities implemented in GSTARS3, one of the la.est versions of the series, are also discussed here with more detail.

关键词： Computer model Reservoir River Sediment transport Unit stream power

Two upper bounds for the Erdos-Hooley Delta-function

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Science China Mathematics 2023年第12期66卷 2683-2692页

作者： Regis de la Breteche Gerald Tenenbaum Institut de Mathematiques Universite Paris CiteSorbonne UniversiteCNRSParis F-75013France Institut Elie Cartan Universite de LorraineVandoeuvre-les-NancyBP 70239France

For integer n≥1 and real u,let Δ(n,u):=|{d:d] n,e^(u) 详细信息

For integer n≥1 and real u,let Δ(n,u):=|{d:d] n,e^(u)

关键词： concentration of divisors average order normal order Waring’s problem

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Concentrations and sources of an emerging pollutant, decabromodiphenylethane (DBDPE), in sewage sludge for land application

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Journal of Environmental Sciences 2012年第3期24卷 558-563页

作者： De la Torre A Concejero M A Martínez M A Persistent Organic Pollutant Group Environment Department CIEMAT Avd. Complutense 22 Madrid 28040 Spain

The presence of an emerging brominated flame retardant, decabromodiphenylethane （DBDPE）, has been confirmed in Spanish sewage sludge. Thirty one samples from different urban wastewater treatment plants （WWTPs） were analyzed for this brominated flame retardant. DBDPE was positively identified and quantified in all samples at lower concentrations （47.0 ± 29.7 ng/g dry weight （dw）; mean ± SD） than those obtained for decabromodiphenyl ether （BDE-209）（290 ± 236 ng/g dw; mean ± SD） in a previous study. Influence of the WWTP characteristics in the pollutant levels was evaluated. No significant correlations were obtained between DBDPE concentrations and the population or sewage sludge production rate associated with the plants, neither wastewater treatment method. Sources of DBDPE in the sludge were also evaluated. Data indicate a common origin for DBDPE and BDE-209, which may be related to leaching processes during the use and disposal of consumer products containing these chemicals. Nevertheless, DBDPE contents are not influenced by industrial activities, which suggests that the infusion of DBDPE commercial mixture is not a source of this chemical into the environment, and indicates that the use of DBDPE in the Spanish industry is still low compared to deca-BDE.

关键词： decabromodiphenylethane polybrominated diphenyl ethers wastewater treatment plants sewage sludge

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Frictional Behavior of a Micro-sized Superconducting Fiber in a Low-Temperature Medium： Experimental and Computational Analysis

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Acta Mechanica Solida Sinica 2018年第4期31卷 405-415页

作者： Shiren la Jun Wang Xingyi Zhang Youhe Zhou Department of Mechanics and Engineering Sciences College of Civil Engineering and Mechanics Lanzhou University Lanzhou 730000 China Key laboratory of Mechanics on Disaster and Environment in Western China Attached to the Ministry of Education of China Lanzhou University Lanzhou 730000 China

The purpose of the current study is to explore the frictional behavior of a micro- sized superconducting fiber at the low-temperature condition. At first, a highly precise tribometer composed of a superconducting fiber wrapping around a cylinder made of pure Cu was immersed in liquid nitrogen. The force and displacement resolutions of the experimental system were as high as 0.01 mN and 0.03 ~m, respectively. The NbTi fibers with diameters ranging from 22.9 to 115 ~m were used in the experiments, and their frictional behaviors in three media, i.e., liquid nitrogen, air and water, were systemically investigated. It was found that the frictional force in air showed a remarkable size effect. The existence of water medium could significantly reduce the frictional force, but could not eliminate the size effect. For the samples with the same diameter, the frictional force in liquid nitrogen was about 1.4 times of that in air, accompanied with remark- able stick-slip phenomenon. Notably, the fiber＇s frictional behavior in liquid nitrogen showed no dependence on diameter. In order to interpret these phenomena, the frictional behaviors of the fibers in air, water and liquid nitrogen were simulated using a modified spring-slider model, by taking into account the influence of hydrophilicity on surface roughness, and the influence of surface roughness on the fiber＇s frictional behavior. The simulation results were consistent with the experimental data qualitatively.

关键词： Micro-sized superconducting fiber Frictional behavior Surface roughness Hydrophilic-ity Stick-slip Size effect Modified spring-slider model

Submicron laB_6 powders with high purity prepared in large scale by salt-assisted combustion synthesis

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Journal of Rare Earths 2018年第6期36卷 623-629页

作者： Zhengning Li Yujing Ou Peiqing la Yu Shi State Key laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of Technology

laB6 powders were synthesized in large scale by salt-assisted combustion synthesis(CS) with different NaCl diluent contents. The variety of phases, particle size and purity of the powders were investigated using X-ray diffraction(XRD), scanning electron microscopy(SEM), energy dispersive spectrometer(EDS), and transmission electron microscope(TEM). With increase of NaCl content, the adiabatic combustion temperature of the reaction system linearly declines, the average particle size of leached products decreases, the impurity phases are easier to remove, and the products purity enhances obviously. When NaCl content is 40 wt%, the purity of the superfine powders of laBis more than 98 wt%, and the average particle size is 380 nm.

关键词： Combustion synthesis laB_6 powders Purity Particle size Rare earths

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A novel sampling method for the investigation of gut microbiota

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World Journal of Gastroenterology 2007年第29期13卷 3990-3995页

作者： Alina Guimares Quintanilha Bruno Zilberstein Manoel A A Santos Denis Pajecki Eduardo Guimares Hourneaux Moura Paulo Roberto Arruda Alves Fauze Maluf-Filho Ivan Cecconello Digestive Surgery Division Department of Gastroenterology and Institute of Biomedical Sciences Department of Microbiology So Paulo University Medical School So Paulo SP Brazil

AIM： In order to characterize the qualitative and quantitative microorganisms in different sites of the lower digestive tract （LDT） in healthy volunteers, a specific technique was developed for collecting mucous of the distal ileum, colon and rectum. METHODS： A polyethylene tube was designed to go through the colonoscope channel with a No. 8 French tube. In order to avoid internal contamination, the distal extremity was protected with a membrane of microfilm after being sterilized in ethilene oxid. To facilitate the aspiration of a precise volume, its interior was coated with silicone. One hundred rnicrolliter （0.1 mL） sample of mucous was collected and transferred into an Eppenddorff tube containing nine hundred rnicrolliter （0.9mL） of VMGA-3 （viable medium of Goteborg）. This procedure was repeated at each site of the LDT with a new sterilized catheter. ResULTS： All sites revealed the ＂non pathogenic＂ anaerobic bacteria Veillonella sp （average 10s colony forming units/mL-CFU/mL）, allowing to conclude an environment of low oxidation-reduction potential （redox） in the LDT. It was also characterized the presence of Klebisiella sp with significant statistical predominance （SSP） in the ileum. Enterobacter sp was found with SSP in the sigrnoid colon, Bacteroides sp non-pigmented （npg） and Ecoli with SSP in the sigrnoid colon and rectum, Enterococcus sp and lactobacillus sp with SSP in the rectum, all in a mean concentration of 10s CFU/mL CONCLUSION： This procedure is feasible and efficient and can point out a similar distribution of the aerobic and anaerobic bacteria with the presence of biological markers of normal microbiota in the LDT.

关键词： Colony count Microbial Fungi Aerobic bacteria Anaerobic bacteria Gastrointestinal endoscopy large Intestine Bacterial translocation Microbiology Catheterization

Olfactory dysfunction in dementia

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World Journal of Clinical Cases 2014年第11期2卷 661-667页

作者： Jorge Alves Agavni Petrosyan Rosana Magalhes Cognitive Rehabilitation Center 4710-228 Braga Portugal Department of Cognitive Sciences Univer-sity of California at Irvine Irvine CA 92717 United States

The natural aging process brings about some inevitable consequences, such as olfactory dysfunction, which is also frequently linked to numerous neurodegenerative disorders. Many age-related dementia, such as Alzheimer's disease, Vascular dementia, Parkinson's disease, and Frontotemporal Dementia often display olfactory dysfunction. Despite the overwhelming evidence of above mentioned facts, the symptomatic relevance and potential clinical and pre-clinical value of olfactory dysfunction remains overlooked by many clinicians and public alike. Olfactory dysfunction has strong practical implications on daily activities and, although not as prominent as in other mammals, olfaction is still an evolutionarily relevant sense involved in human survival(e.g., smelling gas; bad food). In this work, we provide a brief review of current research related to the olfactory dysfunction profiles in different types of dementia. Additionally, we present a compilation of accessible, easy to use olfaction assessment tools; and highlight future directions in terms of improving clinical diagnosis in patient care and research.

关键词： Dementia Aging Olfaction Olfactory dysfunction