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电学性质在研究玻璃析晶过程中的应用

上海建材学院学报 1995年第3期 193-202页

作者：黄文(曰山) c.s.ray D.E.Day 上海建材学院材料工程系 Department of ceramic Engineering and Graduate center for Materials Research University of Missouri-Rolla Rolla MO 65401 U.s.A.

测定了Li2O·2siO2玻璃在不同的核化和晶化条件下的介电常数ε,介电损耗tgδ和电阻率ρ。测试结果表明: ε, tgδ,与ρ均由试样的析晶率所决定;试样在不同温度T_n下核化3 h,然后在660℃温度下晶化15 min,其ε,tgδ与ρ均是核化温度下T_... 详细信息

测定了Li2O·2siO2玻璃在不同的核化和晶化条件下的介电常数ε,介电损耗tgδ和电阻率ρ。测试结果表明: ε, tgδ,与ρ均由试样的析晶率所决定;试样在不同温度T_n下核化3 h,然后在660℃温度下晶化15 min,其ε,tgδ与ρ均是核化温度下T_n的函数,将1/ε对T_n作图,获得的曲线类似于核化速率温度曲线。

关键词：玻璃的核化与晶化电学性质实验方法

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用差热分析测定玻璃析晶过程的核化速率曲线

上海建材学院学报 1993年第3期6卷 187-195页

作者：黄文旵 c.s.ray D.E.Day 上海建材学院 Department of ceramic Engineering and GradLlate center for Materials Research University of Missouri-Rolla

本方法通过对玻璃试样 DTA 数据的处理,改进了玻璃晶化过程中成核速率随温度变化曲线的测定方法。此法比用光学显微镜,对试样中可见晶粒进行计数的传统方法,更快速而简便。本实验确认,Li_2O·2siO_2玻璃的成核速率曲线(I-T)和晶体生长... 详细信息

本方法通过对玻璃试样 DTA 数据的处理,改进了玻璃晶化过程中成核速率随温度变化曲线的测定方法。此法比用光学显微镜,对试样中可见晶粒进行计数的传统方法,更快速而简便。本实验确认,Li_2O·2siO_2玻璃的成核速率曲线(I-T)和晶体生长速度曲线(U-T)不重叠。该系统的 DTA 曲线中,晶体放热峰的高度δT可看成是试样中晶核数量的大小。实验还证明,在确定成核温度范围和成核速率达最大值的最佳温度方面,峰高δT随温度变化的曲线可以代替成核速率 I 随温度变化的曲线。由固体相变理论推出的结论,证明了本实验方法的可行性。

关键词：玻璃成核差热分析

Numerical simulation of square shaped particle sedimentation

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Particuology 2024年第1期84卷 107-116页

作者： Govind sharma Bahni ray Department of Mechanical Engineering Indian Institute of Technology DelhiHauz KhasNew Delhi110016India

Direct numerical simulations of square particle sedimentation in a viscous incompressible fluid are presented to examine the effects of sharp edges for various particle-to-fluid density ratios and different initial inclination *** settling process exhibits four different motion regimes;non-oscillatory,non-uniform centered oscillatory,uniform off-centered oscillatory,and non-uniform off-centered(irregular)*** moderate density ratios,we observe that the rotational motion of settling square particle varies with the initial inclination *** employ Dynamic Time Warping and Fast Fourier Transform to analyze translational and angular *** systems are described using phase-space plots,and a chaotic phenomenon is observed at a higher density ratio.

关键词： sedimentation Distributed Lagrangian multiplier Phase synchronization Oscillations

TALYs calculation and a short review of the experimental status of proton capture studies on p-nuclei:A guide to future investigation

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chinese Physics c 2024年第6期48卷 102-111页

作者： Indrani ray Argha Deb Physics Department Jadavpur UniversityKolkata-700032India

TALYs calculations were performed to obtain the theoretical proton capture cross-sections on the p-nuclei.A short review on the status of related experimental studies was also *** basic properties such as Q-values,coulomb barrier,Gamow peak,Gamow Window,and decay properties of the parent and daughter nuclei were *** experimental parameters,e.g.,beam energy,beam current,targets,and detectors,used in experimental investigations reported in the literature,were *** results of the TALYs calculations in the Gamow region were compared with the corresponding experimental values wherever *** study is expected to facilitate the planning of future experiments.

关键词： p-nuclei proton capture cross-section gamma ray Gamow energy TALYs TENDL KADoNis

A new method for deriving broad-band polar motion geodetic excitations

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Geodesy and Geodynamics 2024年第5期15卷 453-464页

作者： Wei chen Jiesi Luo Jim ray Jiancheng Li Hubei Luojia Laboratory School of Geodesy and GeomaticsWuhan UniversityWuhan 430079China National Oceanic and Atmospheric Administration Silver SpringMDUSA central south University Changsha 410083China

While the geodetic excitationχ(t)of polar motion p(t)is essential to improve our understanding of global mass redistributions and relative motions with respect to the terrestrial frame,the widely adopted method to deriveχ(t)from p(t)has biases in both amplitude and phase *** study has developed a new simple but more accurate method based on the combination of the frequency-and time-domain Liouville's equation(FTLE).The FTLE method has been validated not only with 6-h sampled synthetic excitation series but also with daily and 6-h sampled polar motion measurements as well asχ(t)produced by the interactive webpage tool of the International Earth Rotation and Reference systems service(IERs).Numerical comparisons demonstrate thatχ(t)derived from the FTLE method has superior performances in both the time and frequency domains with respect to that obtained from the widely adopted method or the IERs webpage tool,provided that the input p(t)series has a length around or more than 25 years,which presents no practical limitations since the necessary polar motion data are readily *** FTLE code is provided in the form of Mat Lab function.

关键词： Earth rotation Polar motion Geodetic excitation Liouville's equation Mat Lab

Population Dynamics in an Advective Environment

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communications on Applied Mathematics and computation 2024年第1期6卷 399-430页

作者： King-Yeung Lam ray Lee Yuan Lou Department of Mathematics The Ohio State UniversityColumbusOH43210USA school of Mathematical sciences CMA-Shanghai and MOE-LSCShanghai Jiao Tong UniversityShanghai200240China

We consider a one-dimensional reaction-diffusion equation describing single-and two-species population dynamics in an advective environment,based on the modeling frameworks proposed by Lutscher et *** *** analyze the effect of rate of loss of individuals at both the upstream and downstream *** the single-species case,we prove the existence of the critical domain size and provide explicit formulas in terms of model *** further derive qualitative properties of the critical domain size and show that,in some cases,the critical domain size is either strictly decreasing over all diffusion rates,or monotonically increasing after first decreasing to a *** also consider competition between species differing only in their diffusion *** two species having large diffusion rates,we give a sufficient condition to determine whether the faster or slower diffuser wins the *** also briefly discuss applications of these results to competition in species whose spatial niche is affected by shifting isotherms caused by climate change.

关键词： Reaction-diffusion-advection critical domain size competition climate change

Geochemistry and depositional environment of fuchsite quartzites from sargur Group,western Dharwar craton,India

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Acta Geochimica 2024年第3期43卷 555-570页

作者： c.s.sindhuja G.Harshitha c.Manikyamba K.s.V.subramanyam csIR(council of scientific and Industrial Research)-National Geophysical Research Institute(NGRI) Uppal RoadHyderabad 500007India

Meso-Neoarchean fuchsite quartzites are present in different stratigraphic positions of Dharwar craton including the oldest(~3.3 Ga)sargur Group of western Dharwar *** present study deals with the petro-graphic and geochemical characteristics of the fuchsite quartzites from the Ghattihosahalli belt to evaluate their genesis,depositional setting and the enigma involved in the ancient sedimentation *** major mineral assemblages include quartz,fuchsite,and feldspars along with accessory kyanite and *** geochemical com-positions are characterized by high siO_(2),Al_(2)O_(3),low MgO,caO,strongly enriched cr(1326–6899 ppm),Ba(1165–3653 ppm),sr(46–210 ppm),V(107–868 ppm)and Zn(11–158 ppm)contents compared to the upper continental crust(Ucc).The Ucc normalized rare earth element(REE)patterns are characterized by depleted light REE[(La/sm)Ucc=0.33–0.95]compared to heavy REE[(Gd/Yb)_(Ucc)=0.42–1.65]with conspicuous positive Eu-anomalies(Eu/Eu^(*)=1.35–18.27)characteristic of hydrothermal solutions evidenced through the interlayered *** overall major and trace element systematics reflect a combined mafic-felsic provenance and suggest their deposition at a passive continental margin *** comprehensivefield,petrographic,and geo-chemical studies indicate that these quartzites are infiltrated by cr-richfluids released during high-grade metamorphism of associated ultramafic *** sargur and the subse-quent Dharwar orogeny amalgamated diverse lithounits from different tectonic settings,possibly leading to the release of cr-richfluids and the formation of fuchsite quartzite during or after the *** sug-gest a pre-existing stable crust prior to the sargur Group and the link between orogenic events and various mineral deposits in the Dharwar craton.

关键词： Dharwar craton Ghattihosahalli Fuchsite quartzite Provenance Depositional setting

sexual and Reproductive service Interventions for Menstrual Regulation, safe Abortion, and Post-abortion care and Their Effectiveness During Disaster Response: A Global systematic Review

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International Journal of Disaster Risk science 2024年第3期15卷 359-373页

作者： Nibedita s.ray-Bennett Winifred Ekezie Isha Biswas Nimra Iqbal choudhary David cowie Lasith Dissanayake Lauren Macleod Azukaeogo Nnaji Madhulika sahoo school of Business University of Leicester Avoidable Deaths Network University of Leicester Diabetes Research centre Leicester General Hospital University of Leicester school of social sciences and Humanities Aston University Lifespan and Population Health School of Medicine University of Nottingham school of Public Health and Interdisciplinary studies Auckland University of Technology Faculty of Life sciences and Education University of South Wales West African Regional EcHO (WARE) APIN Public Health Initiatives Department of Anthropology Kalahandi University

sexual and reproductive health(sRH) services are crucial for women especially during disasters, to reduce maternal mortality and morbidity from miscarriages, unsafe abortions, and post-abortion complications. This study explored the sRH interventions provided during disaster response. A systematic review was conducted to identify what menstrual regulation(MR), safe abortion(sA), and post-abortion care(PAc) approaches/interventions exist to promote resilience in the health system in disaster settings; what intervention components were most eff ective; and challenges and opportunities to meeting sRH rights. Five electronic databases were searched, resulting in 4194 records. Following the screening process, seven publications were included. The intervention-related information in each publication was assessed based on availability,accessibility, acceptability, and quality. Two sRH approaches/interventions were found. The eff ectiveness of intervention components could not be conducted due to the limited number of relevant studies. challenges were found at facility and community levels, and opportunities included overcoming them, making MR, sA, and PAc integral to the mitigation phase,and policy change to overcome barriers related to unaff ordability and inaccessibility. Recommendations are provided to encourage research and policy towards improving neglected sRH in disaster settings to realize sustainable Development Goal 3 and the Global strategy and sendai Framework's priority to promote disaster-resilient health systems.

关键词： Abortion Disasters sendai framework sexual and reproductive health sustainable development goal

Early Phases of star Formation: Testing chemical Tools

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Research in Astronomy and Astrophysics 2024年第1期24卷 96-118页

作者： N.c.Martinez s.Paron cONIcET-Universidad de Buenos Aires.Instituto de Astronomía y Física del Espacio Ciudad Universitaria(C1428EGA)Ciudad Autónoma de Buenos AiresArgentina

star-forming processes strongly influence the IsM ***,many high-quality databases are available at millimeter *** them,it is possible to carry out studies that review and deepen previous *** these studies involve large samples of sources,it is preferred to use direct tools to study the molecular *** the aim of testing these tools such as the use of the HcN/HNc ratio as a thermometer,and the use of H^(13)cO^(+),Hc_(3)N,N_(2)H^(+) and c_(2)H as "chemical clocks," we present a molecular line study toward 55 sources representing massive young stellar objects at different evolutionary stages:infrared dark clouds(IRDcs),highmass protostellar objects(HMPOs),hot molecular cores(HMcs) and ultracompact H II *** found that the use of the HcN/HNc ratio as a universal thermometer in the IsM should be taken with care because the HcN optical depth is a big issue that can affect the ***,this tool should be utilized only after a careful analysis of the HcN spectrum,checking that no line,neither the main nor the hyperfine ones,presents absorption *** point out that the analysis of the emission of H^(13)cO^(+),Hc_(3)N,N_(2)H^(+) and c_(2)H could be useful to trace and distinguish regions among IRDcs,HMPOs and *** molecular line widths of these four species increase from the IRDc to the HMc stage,which can be a consequence of the gas dynamics related to the starforming processes taking place in the molecular *** results not only contribute with more statistics,acting as a probe of such chemical tools,useful to obtain information in large samples of sources,but also complement previous works through the analysis of other types of sources.

关键词： stars:formation IsM:molecules IsM:clouds