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Important step towards an understanding of the exotic Z_(c)(3900)

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Science china(Physics,Mechanics & Astronomy) 2024年第9期67卷 199-200页

作者： c.Hanhart Institute for Advanced Simulation Forschungszentrum JulichJilich D-52425Germany

The Standard Model of particle physics,which contains the field theories for the electro-weak interaction(QED)and the strong interaction(QcD),is an extremely successful theory describing a huge variety of phenomena at... 详细信息

关键词： interaction atomic describing

Designing New Alloys with High Strength and Ductility

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材料导报 2020年第13期34卷 13003-13004页

作者： c.Suryanarayana Department of Mechanical and Aerospace Engineering University of Central FloridaOrlandoFL.32816-2450U.S.A

Materials scientists have been constantly on the lookout for materials that simultaneously exhibit high strength and good ductility,which is contrary to common wisdom[1].Earlier attempts to achieve this unusual combination have met with limited success[2].Novel approaches such as a duplex microstructure consisting of nanocrystalline and ultrafine grains yielded encouraging results[3].While the nanocrystalline structure provided high strength,the ultrafine-grained(or relatively coarse-grained)structure provided the needed ductility.

关键词： ductility grain strength

EFFEcT OF cHLORIDE ON THE ATMOSPHERIc cORROSION OF SIMULATED ARTIFAcT IRON IN NO_3^- BEARING POLLUTANT ENVIRONMENT

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Acta Metallurgica Sinica(English Letters) 2006年第1期19卷 34-42页

作者： X. cao c.c. Xu Beijing University of chemical Technology Beijing 100029 China

The effect of chloride in nitrogen-bearing pollutant on the atmospheric corrosion of cast iron was investigated by using periodic wet-dry test, electrochemical experiment and surface tension test. Scanning electron microscopy （SEM） with energy disperse atomic X-ray （EDAX） was used to identify the corrosion processes and products. The results of the weight loss measurement showed that the whale corrosion kinetics can be approximately described by： AW=At^8. With the addition of NacI, B increases. The result presented that cI^- accelerated the corrosion rate obviously during the whale corrosion process. The initial corrosion process was investigated from the viewpoint of surface tension. At the initial corrosion period, the corrosion rate was proportion to the adsorption of anions contained the solutions. And as corrosion went on, the penetration effect of anions and different characteristics of the corrosion products began to dominant the corrosion process, which led to the accelerated effect.

关键词： corrosion simulated archaeological iron corrosion rate chloride,nitrogen-bearing pollutant

Hot cracking in AZ31 and AZ61 Magnesium Alloy

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Journal of Materials Science & Technology 2011年第7期27卷 633-640页

作者： c.J. Huang c.M. cheng c.P. chou F.H. chen Department of Mechanical Engineering National Chiao Tung University Hsinchu 300 Taiwan China Department of Industrial Education National Taiwan Normal University Taipei 106 Taiwan China

This paper examined the impact of the number of thermal cycles and augmented strain on hot cracking in AZ31 and AZ61 magnesium alloy. Statistical analyses were performed. Following observation using a scanning electron microscope （SEM）, an energy dispersive spectrometer （EDS） was used for component analysis. Results showed that Al content in magnesium alloy has an effect on hot cracking susceptibility. In addition, the nonequilibrium solidification process produced segregation in Al content, causing higher liquid Mg-alloy rich Al content at grain boundaries, and resulting into liquefied grain boundaries of partially melted zone （PMZ）. In summary, under multiple thermal cycles AZ61 produced serious liquation cracking. AZ61 has higher （6 wt%） Al content and produced much liquefied Mg17Al12 at grain boundaries under multiple thermal cycles. The liquefied Mg17Al12 were pulled apart and hot cracks formed at weld metal HAZ due to the augmented strain. Since AZ31 had half the Al content of AZ61, its hot-cracking susceptibility was lower than AZ61. In addition, AZ61 showed longer total crack length （TcL） in one thermal cycle compared to that in three thermal cycles. This phenomenon was possibly due to high-temperature gasification of Al during the welding process, which resulted in lower overall Al content. consequently, shorter hot cracks exhibited in three thermal cycles. It was found the Al content of AZ31 and AZ61 can be used to assess the hot-cracking susceptibility.

关键词： Varestraint test Thermal cycles Hot-cracking susceptibility Gas tungsten arc welding (GTAW) AZ31 AZ61

Nitric oxide removal by wastewater bacteria in a biotrickling filter

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Journal of Environmental Sciences 2014年第3期26卷 555-565页

作者： Hejingying Niu Dennis Y c Leung chifat Wong Tong Zhang Mayngor chan Fred c c Leung Department of Mechanical Engineering The University of Hong Kong School of Biological Sciences The University of Hong Kong Department of civil Engineering The University of Hong Kong

Nitric oxide （NO） is one of the most important air pollutants in atmosphere mainly emitted from combustion source. A biotriclding filter was designed and operated to remove NO from an air stream using bacteria extracted from the sewage sludge of a municipal sewage treatment plant. To obtain the best operation conditions for the biotrickling filter, orthogonal experiments （L9（34）） were designed. Inlet oxygen concentration was found to be the most significant factor of the biotrickling filter and has a significant negative effect on the system. The optimal conditions of the biotrickling filter occurred at a temperature of 40℃, a pH of 8.0 and a chemical oxygen demand of 165 mg/L in the recycled water with no oxygen in the system. The bacteria sample was detected by DNA sequencing technology and showed 93%-98% similarity to Pseudomonas mendocina. Moreover, a full gene sequencing results indicated the bacterium was a brand new strain and named as P. mendocina DLHK. This strain can transfer nitrate to organic nitrogen. The result suggested the assimilation nitrogen process in this system. Through the isotope experimental analysis, two intermediate products （^15NO and ^15N2O） were found. The results indicated the denitrification function and capability of the biotrickling filter in removing NO.

关键词： NO reduction biotrickling filter orthogonal experiment Pseudomonas mendocina isotope labeling

Mechanical properties of microcrystalline branching selenite gypsum samples and influence of constituting factors

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第2期11卷 228-241页

作者： c.caselle S.Bonetto c.colombero c.comina Department of Earth Sciences (DST) Università degli Studi di Torino Department of Environment Land and Infrastructure Engineering (DIATI)Politecnico di Torino

The high sedimentological variability of gypsum rocks has the effect that a univocal characterization of this material is not easy to establish. This is particularly true from the geomechanical point of view: when the mechanical properties of gypsum rocks are requested, it is therefore necessary to undertake detailed characterization analyses. common facies of gypsum was observed in the Upper Miocene evaporitic succession(Messinian Salinity crisis) within the whole Mediterranean Basin. In this work, mechanical tests were conducted on a site-specific facies, represented by the microcrystalline branching selenite. The tested samples came from the Monferrato area(northwestern Italy). Uniaxial compressive strength(UcS)tests were performed in order to obtain reference mechanical parameters. More rapid and economic point load test(PLT) and ultrasonic pulse velocity(UPV) measurements were additionally performed to verify their applicability as complementary/alternative methods for site characterization. Rock-type specific PLT-UcS and UPV-UcS relationships were established. A wide dispersion of the mechanical parameters was observed due to the heterogeneities of the studied material. consequently, compositional, textural and microstructural observations on selected samples were performed. Two main material classes were recognized based on average grain size and total gypsum content, underlining the significant influence of the grain sorting on the measured mechanical properties.

关键词： Gypsum Uniaxial compressive strength(UcS) Point load test(PLT) Mechanical properties Geological heterogeneity

combining material characterization with single and multi-oxyanion adsorption for mechanistic study of chromate removal by cationic hydrogel

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Journal of Environmental Sciences 2011年第6期23卷 1004-1010页

作者： Irene M.c.Lo Samuel c.N.Tang Department of civil and Environmental Engineering The Hong Kong University of Science and TechnologyHong KongChina

cationic hydrogel with magnetic property was synthesized via radical polymerization and its removal capacity of chromate from contaminated water was found to be 200 mg/*** Fourier transform infrared spectroscopy（FT-IR） study,the mechanism of chromate removal by hydrogel was found to be non-specific adsorption,mainly due to ion exchange,as evidenced by the positively charged functional group,trimethyl ammonium-N＋（cH3）3,in the *** were accordingly determined by testing di？erent oxyanion adsorption onto the *** results of the chromate adsorption experiments illustrated that the amount of chromate adsorbed was nearly equal to that of the chloride released from the hydrogel,which is part of the evidence for ion *** and multi-oxyanion adsorption experiments were also performed,and it was demonstrated that ion removal was species independent,but charge dependent,another characteristic of the ion exchange *** was found that the same Langmuir model can be applied to best fit the findings of single and multi-oxyanion adsorption,which further indicates the mechanism of chromate removal is attributed to ion *** view of the above,the background anions compete for adsorption sites with chromate,evidenced by inhibitive chromate removal in the presence of background electrolytes in the batch studies,further echoing the ion exchange mechanism.

关键词： adsorption magnetic hydrogel mechanism ion exchange oxyanion

Air quality control in the ART laboratory is a major determinant of IVF success

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Asian Journal of Andrology 2016年第4期18卷 596-599页

作者： Sandro c Esteves Fabiola c Bento ANDROFERT Center for Male Reproduction Av. Dr. Heitor Penteado 1464 Campinas SP 13075-460 Brazil.

Arecently published article described how a fertility center in the UnitedStates implemented air quality control to newly designed in vitro fertilization （IVF） laboratory.1 A highly-efficient air filtration was achieved by installing a centered system supplying filtered air to the IVF laboratory and related critical areas, combining air particulate and volatile organic compound （VOc） filtration. As a consequence, live birth rates were increased by improvements in air quality. This article highlights the key aspects of air contamination in the IVF context. The topic is important not only to IVF specialists but also to Andrologists due to the great number of male infertility patients referred to assisted reproductive technology （ART） treatments. The evidence is growing that laboratory air quality is paramount importance for improved IVF outcome.

关键词： @@

Unveiling the inner structure of electron pulses generated from a laser-wakefield accelerator

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Light(Science & Applications) 2023年第10期12卷 1992-1994页

作者： Malte c.Kaluza Institute of Optics and Quantum Electronics Max-Wien-Platz 107743JenaGermany Helmholtz-Institute Jena Fröbelstieg 307743JenaGermany

A novel diagnostic method has been used to gain deeper insight into the transverse structure and its evolution of electron pulses generated from a laser-wakefield accelerator.

关键词： structure field laser