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Arc erosion of AgSnO_2 electrical contacts at different stages of a break operation

Rare Metals 2010年第3期29卷 248-254页

作者： j. Swingler A. Sumption School of Engineering Sciences University of Southampton

Arc erosion studies are conducted on AgSnO2 contact materials at different stages in the break operation. A resistive load arrangement is used with up to 42 V DC at 24 A and a constant contact opening velocity. The arc current is terminated at different stages as the arc is drawn between the contacts enabling a study of the arcing phenomena up to that point. Surface profiling of the contacts is conducted to determine the extent of erosion at the different stages as the arc is drawn. Spectral analysis is also conducted on the arc and then related to the extent of erosion. The results show that particular features occur at different stages as the arc is drawn. As the arc is initially established, it goes through an ＂Arc Generation＂ regime where the arc roots are small and immobile on both the anode and the cathode. Material transfer occurs mainly from anode to cathode. The spectral analysis indicates that Sn and O species dominate the arc followed by the Ag species. As the arc is drawn further and enters the ＂Arc Degeneration＂ regime, the anode undergoes significantly larger erosion than the cathode. Also, both contacts indicate that multiple arc roots have formed, which are highly mobile in the later stages of the discharge. The spectral analysis indicates that Ag and N species are in high concentrations compared to other species. The mechanisms of erosion and deposition are discussed in relation to the species within the arc discharge. For the complete break operation, it is found that the anode undergoes maj.r erosion, and it is thought that the gaseous ions species do not dominate the arc under these conditions of short arcs and voltage 〈42 V to cause cathode erosion.

关键词： contact materials electrical contacts arc erosion 3D surface profiles spectral analysis

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Small Zeros of Additive Forms in Several Variables

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Acta Mathematica Sinica,English Series 1998年第1期14卷 57-66页

作者： j. S. Hwang Institute of Mathematics Academia Sinica Taipei Taiwan 11529 China

Let f（X） be an additive form defined by f（X）=f（x1. x2,…,xs）=σ1α1x1k+σα2x2k+…+σsαsxsk, where αo≠0 is integer, i=1, 2,…, s. In 1979, Schmidt proved that if ε>0 then there is a large constant C（k, ε） such that for s≥C（k, ε） the equation f（X）=0 has a nontrivial integer solution in σ1. σ2,…σs, x1, x2…,xs satisfying σi=±1 and |xi|≤Aε, i=1, 2.…,s where A=max|ai|. Schmidt did not estimate this constant C（k. ε） since it would be extremely large. In this paper, we prove the following result: Theorem 1 If log A≤1/ε,then C（k,ε）≤max （2/ε,20）; if log A>1/ε,A is sufficiently larye and 1/2A≤5≤|ai|≤A,i=1. 2,…, s, then C（k,ε）≤c1c2p and if the last condition is omitted, then C（k. ε）≤[4/ε]c1c2,where c1={2k+1 for≤k≤11 [5k2log k] for k≥12, c2=100c1k22k+c12 and p=2[log 2c1/ε]. We note that the inequality in the first case is sharp but not in the second case.

关键词： Additive form Subset sums Small zeros

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ON THE ALGORITHMIC COMPLEXITY OF STATIC STRUCTURES

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j.urnal of Systems Science & Complexity 2010年第6期23卷 1037-1053页

作者： j.el RATSABY j. CHASKALOVIC j.el RATSABY Dept. of Electrical and Electronics Engineering Ariel University Center of Samaria Ariel Israel Department of Mathematics Ariel University Center of Samaria Ariel Israel and IJLRDA University Pierre and Marie Curie-Paris VI France.

This paper provides a first indication that this is true for a system comprised of a static structure described by hyperbolic partial differential equations and is subj.cted to an external random input force. The system deforms the randomness of an input force sequence in proportion to its algorithmic complexity. The authors demonstrate this by numerical analysis of a one-dimensional vibrating elastic solid （the system） on which we apply a maximally-random force sequence （input）. The level of complexity of the system is controlled via external parameters. The output response is the field of displacements observed at several positions on the body. The algorithmic complexity and stochasticity of the resulting output displacement sequence is measured and compared against the complexity of the system. The results show that the higher the system complexity, the more random-deficient the output sequence.

关键词： Data compression descriptional complexity randomness static structure.

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The Salt Overly Sensitive （SOS） Pathway： Established and Emerging Roles

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Molecular Plant 2013年第2期6卷 275-286页

作者： Hongtao j. j.sé M. Pardo Giorgia Batelli michael j. Van Oosten Ray A. Bressan Xia Li The State Key Laboratory of Plant Cell and Chromosome Engineering Center of Agricultural Resources Research Institute of Genetics andDevelopmental Biology Chinese Academy of Sciences Shijiazhuang Hebei 050021 PR China Instituto de Recursos Naturales y Agrobiologia Consejo Superior de Investigaciones Cientificas Sevilla-41012 Spain CNR Institute of Plant Genetics (CNR-IGV) Via Universita' i33 80055 Portici Italy Department of Agricultural Engineering and Agronomy University of Naples Federico II Via Universit~ 100 80055 Portici Italy Center for Plant Environmental Stress Physiology Purdue University West Lafayette IN 47907-2010 USA Department Biological Sciences King Abdulaziz University Kingdom of Saudi Arabia

Soil salinity is a growing problem around the world with special relevance in farmlands. The ability to sense and respond to environmental stimuli is among the most fundamental processes that enable plants to survive. At the cellular level, the Salt Overly Sensitive （SOS） signaling pathway that comprises SOS3, SOS2, and SOS1 has been proposed to mediate cellular signaling under salt stress, to maintain ion homeostasis. Less well known is how cellularly heterog- enous organs couple the salt signals to homeostasis maintenance of different types of cells and to appropriate growth of the entire organ and plant. Recent evidence strongly indicates that different regulatory mechanisms are adopted by roots and shoots in response to salt stress. Several reports have stated that, in roots, the SOS proteins may have novel roles in addition to their functions in sodium homeostasis. SOS3 plays a critical role in plastic development of lateral roots through modulation of auxin gradients and maxima in roots under mild salt conditions. The SOS proteins also play a role in the dynamics of cytoskeleton under stress. These results imply a high complexity of the regulatory networks involved in plant response to salinity. This review focuses on the emerging complexity of the SOS signaling and SOS protein functions, and highlights recent understanding on how the SOS proteins contribute to different responses to salt stress besides ion homeostasis.

关键词： auxin ion homeostasis root system architecture salt stress the SOS signaling pathway.

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Prognostic model of survival outcomes in non-small cell lung cancer patients initiated on afatinib: pooled analysis of clinical trial data

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Cancer Biology & Medicine 2019年第2期16卷 341-349页

作者： Ashley M. Hopkins Adel Shahnam Sasha Zhang Chris S. Karapetis Andrew Rowland michael j. Sorich Flinders Centre for Innovation in Cancer Department of Clinical Pharmacology College of Medicine and Public Health Flinders University Adelaide 5042 Australia The Canberra Hospital Garran 2605 Australia

Obj.ctive: Several predictors of survival have been identified in EGFR-positive non-small cell lung cancer(NSCLC) patients treated with first generation EGFR inhibitors. Prognostic models of survival outcomes with afatinib have not been ***: A prognostic tool for overall survival(OS)/progression free survival(PFS) based on pre-treatment clinicopathological factors was developed for EGFR-positive advanced NSCLC patients treated with first-line afatinib using penalised regression of individual-participant data from LUX-Lung 3 and 6(n = 468). Favourable, intermediate and poor risk groups were identified and externally validated using LUX-Lung 1(n = 390) and LUX-Lung 2(n = 129) trials that initiated afatinib following previous chemotherapy or EGFR inhibitor ***: Discriminative performance was good in the development and validation cohorts. For patients treated with first-line afatinib, the median OS for the favourable, intermediate and poor risk groups were > 47.7, 29.3 and 16.4 months, respectively, and the median PFS were 17.3, 13.2 and 8.3 months, respectively. The improvement in median OS with afatinib use compared to chemotherapy was > 12.4 months for the favourable risk group, whereas no OS benefit was apparent for the poor risk group. The improvement in median PFS with afatinib use compared to chemotherapy was 10.2 months for the favourable risk group and 3.2 months for the poor risk ***: A prognostic tool was developed and validated to identify favourable, intermediate and poor risk groups for OS/PFS in EGFR-positive advanced NSCLC patients treated with afatinib. The prognostic groups can inform the likely absolute OS/PFS benefit expected from afatinib compared to chemotherapy in first-line treatment.

关键词： Afatinib non-small cell lung cancer prognostic model

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Nickel-coated silicon photocathode for water splitting in alkaline electrolytes

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Nano Research 2015年第5期8卷 1577-1583页

作者： j. Feng Ming Gong michael j. Kenney j.stin Z. Wu Bo Zhang Yanguang Li Hongj.e Dai Department of Chemistry Stanford University Stanford California 94305 USA Institute of Functional Nano & Soft Materials Soochow University Suzhou 215123 China

Photoelectrochemical （PEC） water splitting is a promising approach to harvest and store solar energy [1]. Silicon has been widely investigated for PEC photoelectrodes due to its suitable band gap （1.12 eV） matching the solar spectrum [2]. Here we investigate employing nickel both as a catalyst and protecting layer of a p-type silicon photocathode for photoelectrochemical hydrogen evolution in basic electrolytes for the first time. The silicon photocathode was made by depositing 15 nm Ti on a p-type silicon wafer followed by 5 nm Ni. The photocathode afforded an onset potential of -0.3 V vs. the reversible hydrogen electrode （RHE） in alkaline solution （1 M KOH）. The stability of the Ni/Ti/p-Si photocathode showed a 100 mV decay over 12 h in KOH, but the stability was significantly improved when the photocathode was operated in potassium borate buffer solution （pH ≈ 9.5）. The electrode surface was found to remain intact after 12 h of continuous operation at a constant current density of 10 mA/cm^2 in potassium borate buffer, suggesting that Ni affords good protection of Si based photocathodes in borate buffers.

关键词： photoelectrochemical water splitting silicon photocathode nickel

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Hole-doping of mechanically exfoliated graphene by confined hydration layers

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Nano Research 2015年第9期8卷 3020-3026页

作者： Tj.erd R. j. Bollmann Liubov Yu. Antipina Matthias Temmen michael Reichling Pavel B. Sorokin Inorganic Materials Science MESA+ Institute for Nanotechnology P. O. Box 217 7500AE Enschede The Netherlands Fachbereich Physik Universitat OsnabrClck BarbarastraBe 7 OsnabrClck 49076 Germany Moscow Institute of Physics and Technology Dolgoprudny 141700 Russian Federation Siberian Federal University Krasnoyarsk 660041 Russian Federation National University of Science and Technology MISiS Moscow 119049 Russian Federation

By the use of non-contact atomic force microscopy （NC-AFM） and Kelvin probe force microscopy （KPFM）, we measure the local surface potential of mechanically exfoliated graphene on the prototypical insulating hydrophilic substrate of CAF2（111）. Hydration layers confined between the graphene and the CaF2 substrate, resulting from the graphene＇s preparation under ambient conditions on the hydrophilic substrate surface, are found to electronically modify the graphene as the material＇s electron density transfers from graphene to the hydration layer. Density functional theory （DFT） calculations predict that the first 2 to 3 water layers adj.cent to the graphene hole-dope the graphene by several percent of a unit charge per unit cell.

关键词： graphene,non-contact atomic forcemicroscopy (NC-AFM,KPFM),liquid-solid interfacestructure,electronic transport innanoscale materials andstructuresgraphene,non-contact atomic forcemicroscopy (NC-AFM,KPFM),liquid-solid interfacestructure,electronic transport innanoscale materials andstructures

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First experience with intracytoplasmic sperm inj.ction for extreme oligozoospermia associated with Crohn's disease and 6-mercaptopurine chemotherapy

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Asian j.urnal of Andrology 2003年第1期5卷 76-78页

作者： E.Scott Sills michael j.Tucker Division of Reproductive Endocrinology and Infertility Department of Obstetrics and Gynecology Atlanta Medical Center AtlantaGeorgia 30342USA

Aim: To describe the reproductive outcome following intracytoplasmic sperm inj.ction (ICSI) for male factor infertility associated with Crohn's disease and 6-mercap-topurine (6-MP) chemotherapy. Methods: The male partner of a couple suffered from severe Crohn's disease and received a 3-month course of 6-MP for this condition. Two spontaneous conceptions were established before 6-MP, although post-chemotherapy semen analysis found the sperm concentration to be 8,000/mL. In vitro fertilization (IVF) with ICSI and embryo transfer was performed. Results: The woman underwent an uncomplicated controlled ovarian hyperstimulation sequence using a combined rec-FSH+hMG protocol, following late luteal phase pituitary downregulation. This culminated in the retrieval of 18 oocytes, 11 of which were fertilized with ICSI. She later delivered a normal male infant without urogenital anomaly. Four nontransferred blastocysts were cryopreserved. Conclusion: This report describes the first successful birth after ICSI for severe oligozoospermia associated with Crohn's disease and 6-MP therapy. We outline salient features of Crohn's disease, 6-MP pharmacology, and their relevance to human fertility.

关键词： 6-mercaptopurine chemotherapy infertility ICSI

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Conservation laws for energy and momentum in curved spaces

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j.urnal of Zhej.ang University-Science A(Applied Physics & Engineering) 2007年第4期8卷 665-668页

作者： LóPEZ-BONILLA j. MORALES j. OVANDO G. Section of Postgraduate Studies and Research Superior School of Mechanical and Electrical EngineeringNational Polytechnic InstituteCP 07738Mexico Division of Basic Sciences and Engineering Autonomous Metropolitan UniversityCP 02200Mexico

In arbitrary Riemannian 4-spaces, continuity equations are constructed which could be interpreted as conservation laws for the energy and momentum of the gravitational field. Special attention is given to general relativity to obtain, of natural manner, the pseudotensors of Einstein, Landau-Lifshitz, Moeller, Goldberg and Stachel, and also the conservation equations of Komar, Trautman, DuPlessis and Moss.

关键词： Noether theorem Lagrangians in curved spaces Energy and momentum in Riemannian spaces Rund-Lovelock identities

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Floor dust erosion during early stages of coal dust explosion development

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International j.urnal of Mining Science and Technology 2019年第6期29卷 825-830页

作者： Marcia L.Harris michael j.Sapko Center for Disease Control and Prevention (CDC) National Institute for Occupational Safety and Health (NIOSH) Pittsburgh Mining Research Division (PMRD)

An ignition of methane and air can generate enough air flow to raise mixtures of combustible coal and rock *** expanding high temperature combustion products ignite the suspended dust mixture and will continue to propagate following the available combustible fuel *** the concentration of the dispersed rock dust is sufficient,the flame will stop ***-scale explosion tests were conducted within the National Institute for Occupational Safety and Health(NIOSH)Lake Lynn Experimental Mine(LLEM)to measure the dynamic pressure history and the post-explosion dust scour *** aim of this effort is to provide quantitative data on depth of dust removal during the early stages of explosion development and its relationship to the depth of floor dust collected for assessing the incombustible content most likely to participate in the combustion *** experimental work on dust removal on is not only important for coal mine safety but also for industrial dust explosions.

关键词： Underground Coal dust Explosion Dust sampling

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