657 research outputs found
Genetic diversity and biogeography of Cunninghamia konishii (Cupressaceae), an island species in Taiwan: a comparison with Cunninghamia lanceolata, a mainland species in China
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Asterolaurins A-F, Xenicane Diterpenoids from the Taiwanese Soft Coral Asterospicularia laurae
No full textFungi Genus and Concentration in the Air of Onion Fields and its Opportunistic Action Related to Mycotic Keratitis
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Segmentation and crustal structure of the western Mid-Atlantic Ridge flank, 25°25′–27°10′N and 0–29 m.y.
No full textAuthor Posting. © American Geophysical Union, 1997. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 102, no. B5 (1997): 10203–10223, doi:10.1029/96JB03896.We conducted a detailed geological-geophysical survey of the west flank of the Mid-Atlantic Ridge between 25°25′N and 27°10′N and from the ridge axis out to 29 Ma crust, acquiring Hydrosweep multibeam bathymetry, HAWAII MR1 sidescan-sonar imagery, gravity, magnetics, and single-channel seismic reflection profiles. The survey covered all or part of nine spreading segments bounded by mostly nontransform, right-stepping discontinuities which are subparallel to flow lines but which migrated independently of one another. Some discontinuities alternated between small right- and left-stepping offsets or exhibited zero offset for up to 3–4 m.y. Despite these changes, the spreading segments have been long-lived and extend 20 m.y. or more across isochrons. A large shift (∼9°) in relative plate motion about 24–22 Ma caused significant changes in segmentation pattern. The nature of this plate-boundary response, together with the persistence of segments through periods of zero offset at their bounding discontinuities, suggest that the position and longevity of segments are controlled primarily by the subaxial position of buoyant mantle diapirs or focused zones of rising melt. Within segments, there are distinct differences in seafloor depth, morphology, residual mantle Bouguer gravity anomaly, and apparent crustal thickness between inside-corner and outside-corner crust. This demands fundamentally asymmetric crustal accretion and extension across the ridge axis, which we attribute to low-angle, detachment faulting near segment ends. Cyclic variations in residual gravity over the crossisochron run of segments also suggest crustal-thickness changes of at least 1–2 km every 2–3 m.y. These are interpreted to be caused by episodes of magmatic versus relatively amagmatic extension, controlled by retention and quasiperiodic release of melt from the upwelling mantle. Detachment faulting appears to be especially effective in exhuming lower crust to upper mantle at inside corners during relatively amagmatic episodes, creating crustal domes analogous to “turtleback” metamorphic core complexes that are formed by low-angle, detachment faulting in subaerial extensional environments.This research was supported by ONR grants N00014-90-J-1621 and N00014-94-1-0466 and NSF grant OCE-9300708
Delocalization by disorder in GaAs/AlGaAs heterostructures
No full textAn experimental study of quasiparticle and quasi-one dimensional properties of strongly correlated two-dimensional (2D) electron systems has been carried out. The samples were low disordered
GaAs/AlGaAs heterostructures. Measurements were performed at low temperatures, down to 24 mK, in a dilution refrigerator (MCK 50-100 TOF) equipped with a superconducting magnet.
The goal of our work was to study quasiparticle properties of 2DEG and to investigate the effect of local disorder on the conductance of the sample.
We have performed independent measurements of effective electron mass m*, transport and quantum scattering time at three different temperatures and effective g-factor. We used Shubnokov de Haas
effect , the oscillations in the longitudinal resistance in Hall effect to study the effective mass, scattering lifetimes and effective g factor. We found out that effective mass is unaffected and agrees well with
the typical value of GaAs/AlGaAs system i.e. 0.067 me, where me is the electron mass. The quantum scattering time was studied at three different temperatures, base temperature (24mK), 200 mK and
400 mK as function of electron density. We found out that the quantum scattering time at 24 mK is independent of electron density while at higher temperatures it decreases with decrease in density.
The ratio of two lifetimes τ_t and τ_q is more than 10 for all temperatures. It means that remote Coulomb centres play a dominating role in the scattering mechanisms of our sample.
More insight is needed to study the quantum scattering time at higher temperatures. The effective g-factor experiments were done with and without in-plane magnetic field. In both cases, the g-factor shows
dependence on the magnetic field.
The main purpose of this thesis work is to investigate possible breakdown of the Anderson localization in presence of local disorder. To implement the local disorder and create delocalization
we have used fine surface gates which tuned the potential barriers in the 2DEG. This was done in two different types of samples. In one sample the finger gates and top surface gate are isolated by
an insulating layer of SiO2 and in the other sample, the two gates are intercalated. The spacing in between the finger gates is determined by the mean free path of the system. The experiments are done in
absence of magnetic field. We found out that the sample with SiO2shows the effect of disorder with decrease in the resistance. But due to charge trapped in the SiO2layer, the effect was not repeated.
In the intercalated samples with two different finger gate spacings, the effect was not visible. The delocalization was not set in these sample even at high temperatures. More study is needed to prove this
effect in GaAs/AlGaAs heterostructures. A low mobility wafer can be considered as the future candidate for this experiment
The Currency and Change of Compendia of Model Writings of Wang XiZhi（集王羲之行書）in Northern Song Dynasty
No full text本文以「集王羲之行書」（以下簡稱「集王行書」）為風格脈絡，討論該書風在北宋的流傳情形。若以題跋文字與傳世墨跡來研究，「集王行書」在此期的樣貌無法完全呈現。然而藉由金石書籍與石刻史料的運用，可以勾勒出「集王行書」在此期的流變。筆者用「集王行書」而不用僧懷仁〈集字聖教序〉這一作品，主要是從北宗的金石書籍與題跋文字無法得知當時有影響力的文人見過僧懷仁〈集字聖教序〉，但見過「集王行書」，「集王行書」大量出現在北宋的金石著錄而非題跋文字，這和石刻書跡的傳真性不足以作為書法的學習，因此不被北宋文人接受有關。最後藉由石刻史料的運用，勾勒出 「集王行書」在北宋的流 行脈絡 。在宋真 朝以前和唐代的關 係密切，分別存在於佛教系統與宮廷系統，且書風無 太大改變。唐代宮廷系統的「集王行書」用於皇室墓誌；北宋宮廷系統的「集王行書」，又稱「院體」，用於對外的官方文告。宋哲宗朝以後， 佛教系統消失；宮廷系統的「院體」產生了變化，這 和院體書吏由伎術官轉換成士流的 管道，從北宋真宗 至神宗朝逐次削減有相當的影響 。This essay discusses the development of Compendia of Model Writings of Wang XiZhi in the Northern Song dynasty (960-1126) based on its context. However, images of this style cannot be seen from the colophons or the hand writings which still remain nowadays, but directly through the books of Epigraphy and stone carving, we can draw the contour of the currency and change of Compendia of Model Writings of Wang XiZhi. From the colophons there is no proof that any of the literati who had great influence on calligraphy had seen“Preface to Sacred Teachings”（集字聖教序）, so the author uses the term Compendia of Model Writings of Wang XiZhi instead of “Preface to Sacred Teachings”, but it is known that they had seen Compendia of Model Writings of Wang XiZhi. This essay first intends to discuss if Compendia of Model Writings of Wang
XiZhi and“Preface to Sacred Teachings” have the same concept of style. Secondly, this essay intends to explain why Compendia of Model Writings of Wang XiZhi appeared in the Northern Song Epigraphy documents but did not appear in the colophons of the same period. This is related to their writing style. Compendia of Model Writings of Wang XiZhi belongs to stone carving, and to copy or use that style as the model of calligraphy learning was not accepted by the Northern Song literati. The author then uses the historical materials from stone carvings to describe the trend of using or learning Compendia of Model Writings of Wang XiZhi in the Northern Song dynasty. Before the rein of Emperor Zhenzong (998-1022), there had been an intimate relationship with Tang Dynasty style, the style that had been practiced separately for Buddhist writing and also court writing, and this style didn’t change much. After the rein of Emperor Zhezong (1086-1100), it disappeared from Buddhism writing, and
Compendia of Model Writings of Wang XiZhi in court, known as “academy style (Yuanti)” had changed. The reason for this change was that the channel of becoming scholar-officials from the skilled officials changed during the rein of Emperor Zhenzong to Shenzong (1023-1085) with fewer high officials drawn from the ranks of the court writing officials
Writings and Publications of the French Nobility under the Absolute Monarchy: La Rochefoucauld's <i>Maximes morales</i> and his Readers' Responses
No full text在法國17世紀尚文著述的佩劍貴族中，曾經參與投石黨運動、對抗王權的拉侯什傅科公爵（Fran?ois VI de la Rochefoucauld, duc et pair de France, 1613-1680），是文學史上經典之作《道德箴言錄》（Maximes morales）的作者。本文嘗試重建拉氏的政治經驗，和其書寫與出版實踐之間的連結關係，指出絕對王權對於貴族用以界定與鞏固同盟關係與恩庇扈從體系之倫理道德的破壞，為拉氏省視個人政治經驗的核心關懷。本文同時透過分析讀者對於《道德箴言錄》的迴響與挪用，檢視17世紀下半葉貴族社群與王權不斷調整的互動與對話關係，並勾勒《道德箴言錄》自17世紀首次出版到18世紀百年之間意義變遷的閱讀史圖像。Among the French nobles of the Sword who engaged in literary writings, the Duke of La Rochefoucauld, former member of the Fronde against the monarchy, was the author of the literary classic, Maximes morales. This article intends to build the connection which existed between the political experiences of La Rochefoucauld and his practices in writing and publication. Duke criticized that the Absolute Monarchy destroyed the ethics which the nobility had used to define and strengthen the relationship of alliance as well as of patron-client. By analyzing the responses and appropriations of the readers of Maximes morales, especially the Parisian elite, this article depicts not only the interaction and dialogue established between the aristocratic community and the monarchy under the rule of Louis XIV, but also a history of reading in which the meaning of Maximes morales shifted from its first publication in the seventeen-century to the eighteenth-century
Periodic review (s, S) inventory model with permissible delay in payments
No full textThis paper investigates the effect of permissible delay in payments on ordering policies in a periodic review (s, S) inventory model with stochastic demand. A new mathematical model is developed, which is an extension to that of Veinott and Wagner (Mngt Sci 1965; 11: 525) who applied renewal theory and stationary probabilistic analysis to determine the equivalent average cost per review period. The performance of the model is validated using a custom-built simulation programme. In addition, two distribution-free heuristic methods of reasonable accuracy develop approximate optimal policies for practical purposes based only on the mean and the standard deviation of the demand. Numerical examples are presented with results discussed.AGGARWAL SP, 1995, J OPER RES SOC, V46, P658, DOI 10.1057-jors.1995.90; ARCELUS FJ, 1993, J OPER RES SOC, V44, P785, DOI 10.1057-jors.1993.137; Arrow KJ, 1951, ECONOMETRICA, V19, P250, DOI 10.2307-1906813; BANERJEE A, 1986, DECISION SCI, V17, P292, DOI 10.1111-j.1540-5915.1986.tb00228.x; CHAND S, 1987, J OPER RES SOC, V38, P83, DOI 10.2307-2582525; CHAPMAN CB, 1984, J OPER RES SOC, V35, P1055, DOI 10.2307-2582093; Chu P, 1998, COMPUT OPER RES, V25, P817, DOI 10.1016-S0305-0548(98)00006-9; CHUNG KH, 1989, J OPER RES SOC, V40, P495; Chung KJ, 1998, COMPUT OPER RES, V25, P49, DOI 10.1016-S0305-0548(97)00041-5; DAVIS RA, 1985, MANAGE SCI, V31, P499, DOI 10.1287-mnsc.31.4.499; EHRHARDT R, 1979, MANAGE SCI, V25, P777, DOI 10.1287-mnsc.25.8.777; EHRHARDT R, 1984, MANAGE SCI, V30, P618, DOI 10.1287-mnsc.30.5.618; FEDERGRUEN A, 1984, OPER RES, V32, P1268, DOI 10.1287-opre.32.6.1268; Fu MC, 1997, IIE TRANS, V29, P191; GOYAL SK, 1985, J OPER RES SOC, V36, P335, DOI 10.2307-2582421; HALEY CW, 1973, MANAGE SCI B-APPL, V20, P464, DOI 10.1287-mnsc.20.4.464; Hwang H, 1997, COMPUT OPER RES, V24, P539, DOI 10.1016-S0305-0548(96)00069-X; IGLEHART DL, 1963, MANAGE SCI, V9, P259, DOI 10.1287-mnsc.9.2.259; JAGGI CK, 1994, INT J PROD ECON, V34, P151, DOI 10.1016-0925-5273(94)90031-0; Jamal AMM, 1997, J OPER RES SOC, V48, P826, DOI 10.2307-3010710; Jamal AMM, 2000, INT J PROD ECON, V66, P59, DOI 10.1016-S0925-5273(99)00108-5; Johansen SG, 1999, INT J PROD ECON, V59, P405, DOI 10.1016-S0925-5273(98)00107-8; Khouja M, 1996, J MANUF SYST, V15, P334, DOI 10.1016-0278-6125(96)84196-3; KIM J, 1995, PROD PLAN CONTROL, V6, P45, DOI 10.1080-09537289508930252; KINGSMAN BG, 1983, J OPER RES SOC, V34, P1085, DOI 10.2307-2581018; Law A., 1991, SIMULATION MODELING; Liao HC, 2000, INT J PROD ECON, V63, P207, DOI 10.1016-S0925-5273(99)00015-8; RACHAMADUGU R, 1989, J OPER RES SOC, V40, P805, DOI 10.1057-jors.1989.143; SAHIN I, 1989, REGENERATIVE INVENTO; Sarker BR, 2000, COMPUT OPER RES, V27, P59, DOI 10.1016-S0305-0548(99)00008-8; SCHNEIDER H, 1990, MANAGE SCI, V36, P822, DOI 10.1287-mnsc.36.7.822; Shah V. R., 1996, Opsearch, V33; Shinn SW, 1996, EUR J OPER RES, V91, P528; Shinn SW, 1997, COMPUT IND ENG, V33, P717, DOI 10.1016-S0360-8352(97)00230-1; Silver E.A., 1998, INVENTORY MANAGEMENT; Teng JT, 2002, J OPER RES SOC, V53, P915, DOI 10.1057-palgrave.jors.2601410; VEINOTT AF, 1965, MANAGE SCI, V11, P525, DOI 10.1287-mnsc.11.5.525; Wagner H. M., 1975, PRINCIPLES OPERATION; ZHENG YS, 1991, OPER RES, V39, P654, DOI 10.1287-opre.39.4.65417191
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