87 research outputs found
Initial stages of salt crystal dissolution determined with ab initio molecular dynamics
No full textThe initial stages of NaCl dissolution in liquid water have been examined with state-of-the-art ab initio molecular dynamics and free energy sampling techniques. Our simulations reveal a complex multi-step process triggered by the departure of Cl ions from the lattice, with a well-defined intermediate state wherein departing ions are partially solvated but remain in contact with the crystal. The polarizability of Cl- is identified as the source of the anion's preferential initial dissolution, an effect which leads a forcefield based description of NaCl dissolution to fail to identify a preference for Cl over Na dissolution
Photosynthetic characteristics and accummlation of assimilate of the different pear (Pyrus) grafting combinations
No full text本研究旨在比較幾種高接梨組合的光合作用及碳水化合物累積特性與耐熱性。結果顯示嫁接在以糖梨(Tan Li)為根砧之橫山梨枝幹上的臺灣野梨(P. koehnei)及鳥梨(Laio Li)枝條，其儲藏性碳水化合物較橫山梨枝條為高，而臺灣野梨枝條又較鳥梨高。觀察已嫁接鳥梨之五年橫山梨植株，顯示比未嫁接鳥梨者有較旺的樹勢。但是本研究顯示單位葉面積之光合速率則是鳥梨>橫山梨>臺灣野梨，故嫁接於橫山梨之臺灣野梨枝條能累積較多的同化產物，其原因並非受到單位葉面積之光合速率之影響，可能由於臺灣野梨之葉片數目較多及葉齡較長所致。雖然葉綠素螢光參數顯示臺灣野梨、橫山梨和新興梨(Sinkou)之間光系統Ⅱ之耐熱性並無顯著差異，但是以紅外線分析儀所測得之結果顯示，臺灣野梨之光合適溫稍高於橫山梨及新興梨，此點也可能造成其在台灣中部之高溫環境下能維持稍高的光合速率的原因。由於溫室效應，全球氣溫逐年增加，臺灣野梨較能適應高溫環境及其本身特性，應用在嫁接上可能更有助於改善橫山梨樹勢。The aim of this study focus on the photosynthesis, accumulation of carbohydrate and heat tolerance of difference pear (Pyrus) grafting combinations. The results showed that the branch of both P. koehnei and ‘Laio Li' accumulated higher carbohydrate than that of ‘Heng Shan' in the branch when they were grafted to ‘Tan Li' rootstock. Furthermore, accumulated carbohydrate in the branch of P. koehnei was higher that that of ‘Laio Li'. The growth potential of ‘Heng Shan' was higher in which one branch was grafted with ‘Laio Li' for 5 years than that no grafted. However, photosynthetic rate of leaf area unit of ‘Laio Li' leaves was higher than that of P. koehnei, when they were grafted to ‘Heng Shan'. Above results indicated that the branch of grafted P. koehnei accumulated more photosynthate was not due to the higher photosynthetic rate of leaf area unit rather than higher leaf number as well as longer leaf span. In spite of the temperature tolerance of photosystem Ⅱ estimated from chlorophyll fluorescence was not significant difference among P. koehnei, ‘Heng Shan' and ‘Sinkou' pear, the optimum temperature for photosynthesis of P. koehnei leaves was higher than that of both ‘Heng Shan' and grafted ‘Sinkou'. This result demonstrated that P. koehnei leaves could maintain higher photosynthesis rate during high temperature period in Central of Taiwan. From the above results it could be considered that P. koehnei might be used as a carbon source for pear production under increasing temperature of global climate change.數種高接梨組合之光合作用與同化產物累積特性
目 錄
摘要………………………………………………………………………I
英文摘要………………………………………………………………..Ⅱ
圖目次…………………………………………………………………..Ⅲ
表目次…………………………………………………………………..Ⅴ
壹、前言……………………………………………………….…………1
貳、前人研究………………………………………………….…………4
參、材料與方法…………………………………………………………16
一. 試驗材料……………………………………………………......16
二. 試驗方法……………………………………………………......16
肆、結果…………………………………………………………………22
一. 光合作用特性………………………………………………..22
二. 葉綠素螢光對溫度之反應…………………………………..28
三. 葉片老化葉綠素變化情形…………………………………..32
四. 休眠期碳水化合物儲藏特性………………………………..35
伍、討論………………………………………………………………..39
陸、結論………………………………………………………………..43
引用文獻………………………………………………………………..44
附錄照片………………………………………………………………..5
Molecular dynamics simulation of reconstructive phase transitions on an anhydrous zeolite
No full textThe structural transformation of a framework aluminosilicate, Li-ABW, is studied using molecular dynamics. The calculations are carried out by applying the method presented by Martoňák et al. [Phys. Rev. Lett. 90, 075503 (2003)], that allows for the exploration of the Gibbs free energy as a function of the cell parameters by history-dependent dynamics. We show that this technique allows for an extensive exploration of the phase space also for complex polyatomic material, such as a zeolite, and allows for the successful prediction of a reconstructive phase transition at the pressure and temperature of experimental relevance. In particular, we observe a reconstructive transition from anhydrous Li-ABW to eucryptite at the temperature of ∼920 K, as experimentally observed. The steps initiating the transformation and the transition pathway are discussed
Statistical Hydrology
No full textHydrological phenomena such as precipitation, floods, and droughts are inherently random by nature. Due to the complexity of the hydrologic system, these physical processes are not fully understood and reliable deterministic mathematical models are still to be developed. Therefore, in order to provide useful analyses for designing hydraulic facilities and infrastructures, statistical approaches have been commonly adopted.
This chapter describes some statistical topics widely used in hydrology. Among the large number of subjects available in literature, the attention is focalized on some of them particularly useful either for innovative hydrological analyses or for an appropriate application of common procedures.
Precisely, the chapter describes in details the stationary hypothesis on hydrological time series, the univariate extreme value analysis procedure, the intensity–duration–frequency curves, the copula function useful for multivariate analysis, and the regional flood frequency analysis.
Author Keywords: Copula function; Extreme rainfall analysis; Extreme value analysis; Goodness-of-fit tests; IDF – intensity duration frequency curves; L-moments; Multivariate distributions; Nonstationary time series; Regional index flood; RFFA – regional flood frequency analysis; Time series segmentation; Trend detectio
The Cultivars of Litchi (Litchi chinensis Sonn.) and Their Improvement in Taiwan
No full text荔枝育種計劃始於民國71年，主要工作爲種源蒐集，自然授粉實生選種及人工雜交育種，育種目標爲不同產期、豐產、適應性、優良品質及風味、大果及高小率等。初步自本省調查獲20已命名品種及21變異品系，並選出4個具有早熟、豐產及高小核率之優良品系。依果實性狀可將本省荔枝品種分成三大系統。
荔枝開花及授粉方式於本文中另加討論，爲增加自然雜交授粉比率，設立多品種雜交基因庫，包括14主要品種。於前2年自本省各地自然授粉果園獲得約2500株實生苗已密植田間供選種。人工雜交授粉以港尾，淮荔，沙坑及黑葉等品種之着果率較高，較適宜爲授粉母本。爲提高育種效率，已採行密植及縮短幼年期等方法，於本文中詳加討論。
The litchi (Litchi chinensis, Sonn,) breeding program mainly including germplasm. collection and selection of seedlings from open-and controlled-pollioation was started in Taiwan in 1982. Twenty cultivars and 21 selections collected locally ware evaluated. The cultivars capable of providing superior gene sources were discussed. Four promising selections of high yielding, high quality, earliness and with high percentage of small-seeded fruits will be further evaluated. The breeding goals are listed as follows according to priority (in parentheses are the varieties that may provide the gene sources):
1. Various mature seasons to extend the supply of litchi in Taiwan (very early-Sun Yueh Hong, very late-Hwai Li).
2. High yielding and wide adaptability (Hak IP).
3. High quality and sweet fragrance (Yu Her Pan and No Mai Tsz).
4. Large fruit size (Yu Her Pau, Sun Yueh Hong and Sah Keng).
5. High percentage of small-seeded fruits (No Mei Tsz, Yu Her Pau and Sah Keng).
6. Fruit with bright and colorful red skin and smooth protuberances (No Mai Tsz and Kwsi Mi).
7. Vigorous (Yu Her Pau).
8. Processing for dried litchi nut (No Mai Tsz).
9. Long storage life.
10. Resistant to pests and diseases (downy blight, fruit borer and longicorn beetle) as well as low percentage of skin-cracking fruits.
According to fruit characters, the collections of litchi were divided into three distinct group:
Group Ⅰ (or Hon Li Group): Usually early and mature during early June in Chic Yi ares. Fruit oblong to ovoid, bright red, with distict protuberances, and generally large seeded. Fruit weighs between 20 to 25 grams. This group includes Kau Shiung Early, Vu Her Pau, Hon Pi, Foo Chow, Wan Nien Hong and Chung Yuan Hong.
Group Ⅱ (or Hak Ip Group): Mature during middle and late June in Chic Yi. Fruit cordate and dark red; protuberances usually turn smooth toward maturity. Fruit weighs about 20 grams. This group includes Hak Ip, Kwang Tung, Rang Wei Late, Sah Keng sad Sun Yueh Hong.
Group Ⅲ (or Kwai Mi Group): Generally late and mature during early July in Chia Yi. Fruit nearly globular and colorfully red; rough protuberances usually turn smooth toward maturity. Fruit weighs between 17 to 22 grams. Generally a specific fragrance could be tasted in aril in most varieties of this group and its content varied with different varieties. The acid content of fruit decrease rapidly and is eatable when the skin just turns light red. This group includes Kwai Mi, No Mai Tsz, Hwai Li, Hwai Chih, Kwai Chih, Shang Shu Hwai, Tang Po and Hsin Hsin.
The flowering behavior and pollination techniques were discussed, and both open-and controlled-pollination were followed in litchi breeding program. An multi-varieties gene pool orchard composed of 14 varieties with 9 replications was established to increase the hybridization ratio under natural condition. In the first 2 years, totaling about 2500 seedlings were collected from open-pollinated orchard and planted for future selection. Controlled-pollination was also conducted to combine superior characters as well as to overcome the difference in flowering time between early and late varieties that could not be hybridized under natural condition. From fruit-sets obtained in controlled hybridization indicated that Kang Wei, Hwai Li, Sah Keng and Hak Ip could set more fruits and were more suitable as mother plant than other varieties in controlled- pollination.
The methods to increase the efficiency of breeding litchi were tested. Handling the seedling with high population density was practiced to reduce the cost and save the land use. Top-working and the possibility of chemical sprays to shorten the juvenile phase were discussed
[[alternative]]Integral Points on Elliptic Curves
No full text[[abstract]]Let E be an elliptic curve over Q. A well-known theorem of Siegel asserts that the
number of integral points on E is finite. So, for a given elliptic curve E over Q, it would
be interesting to find all the integral points. In [Za], Zagier describes several methods for
explicitly computing large integral points on elliptic curves defined over Q. In this thesis,
follow the line of [ST1], we shall discuss a method of computing all the integral points on an
elliptic curve over Q under the hypothesis that a basis for the free part of the Mordell-Weil
group is given.
In [ST1], R. J. Stroeker and N. Tzanakis adopt a natural approach, in which the linear
relation between an integral point and the generators of the free part of the Mordell-Weil
group is directly transformed into a linear form in elliptic logarithms. In order to produce
upper bounds for the coefficients in the original linear relation, we need an effective lower
bound for the linear form in elliptic logarithms. Thanks to S. David [D, Th´eor`eme 2.1], such
an explicit lower bound was established. The upper bound for the linear form in elliptic
logarithms was established in [ST1], where one needs to deduce an upper bound for the
function (see section 2.2) described in [Za].
In section 2, we discuss three main inequalities which are given in [ST1], as well as a special
case of David’s lower bound which is described in the appendix of [ST1]. In section 3, by
combining the main inequalities and David’s lower bound, we obtain an upper bound for the
coefficients in the original linear relation. However, the upper bound obtained in section 3 is
too large to search all the integral points. So, we need to apply the LLL-reduction procedure
to reduce the upper bound of the coefficients. This will constitute section 4. In the final
section, some examples are given.
Utilizing QFD and TRIZ Techniques to Design a Helmet Combined with the Wireless Camcorder
No full textSull'Edipo Re
No full textL’ "Edipo Re" di Sofocle narra di una profezia infausta che si avvera attraverso le azioni volte a evitarne l’avverarsi. Ma Laio ed Edipo, che danno luogo appunto a tali azioni, credono o non credono nella profezia che li minaccia? Se vi credessero non farebbero nulla per evitarne l’avverarsi, perché riterrebbero che nulla potrebbe impedirlo. Se non vi credessero non farebbero nulla per congiurarla, perché non la riterrebbero destinata ad avverarsi. Se fossero in dubbio se credervi oi non credervi, resterebbe il fatto che in un caso non avrebbero nulla da sperare, nell’altro nulla da temere. Se insieme, contemporaneamente vi credessero e non vi credessero, in virtù del credervi non farebbero nulla, in virtù del non credervi non farebbero nulla. Essi dunque né credono nella profezia, né non vi credono, né sono in dubbio se credervi o non credervi, né vi credono e insieme non vi credono? Qual è allora il loro rapporto con la profezia? Rinunciare a individuarlo significherebbe rinunciare a comprendere il nucleo più profondo della tragedia. Il saggio risponde appunto a questa domanda: Laio ed Edipo credono nella profezia in un modo che racchiude il non credervi; oppure non vi credono in un modo che racchiude il credervi. Se essi agiscono, infatti, vuol dire che ritengono che ci sia bisogno di farlo, che ci si debba adoperare per evitare l’avverarsi della profezia. E ciò – la pura considerazione del bisogno di agire – implica il credere nella profezia. Ma se essi agiscono, vuol dire anche che ritengono possibile farlo, che ritengono possibile evitare l’avverarsi della profezia. E ciò – la pura considerazione della possibilità di agire – implica il non credere nella profezia. Laio ed Edipo, cioè, concepiscono l’intenzione di agire per scongiurare l’avverarsi della profezia in quanto ritengono necessario farlo, dunque in quanto credono nella profezia. Ma se poi concretamente agiscono ciò avviene in quanto ritengono possibile farlo, dunque in quanto non credono nella profezia. E’ l’atto del credere nella profezia a dare luogo a un comportamento che implica il non credervi. Il non credervi è dunque dentro l’atto del credervi, è racchiuso in esso. Questa stessa questione può essere posta nei termini inversi: Laio ed Edipo concepiscono l’intenzione di agire in quanto ritengono possibile farlo, dunque in quanto non credono nella profezia, ma se poi concretamente agiscono ciò avviene in quanto ritengono necessario farlo, dunque in quanto credono nella profezia. In questi termini, è l’atto del non credere a dare luogo a un comportamento che implica il credere. In questo senso, il credere è dentro il non credere. In definita il credere racchiude il non credere in quello stesso contenuto e, viceversa, il non credere racchiude il credere. Il saggio si sviluppa e si conclude argomentando il significato più ampio di tale implicazione reciproca del credere e del non credere, fino a identificare in essa la risposta alla domanda: “che cosa significa credere?”.
(Libro segnalato su “La Repubblica”, 24 giugno 2012 e recensito sulla rivista online “Recensioni filosofiche”, 27 dicembre 2012)
Capeaux in the Brazil mirror: perspectives for a critical reading of the brazilian literature
No full textAs histórias da crítica e da literatura misturam-se ao longo de um dado processo cultural. Entretanto, o processo de formação de cada uma tem suas particularidades. Sendo assim, buscar-se-á, ao traçar um resumido trajeto da história da crítica literária brasileira, situar a atividade crítica de Otto Maria Carpeaux, contrapondo-o a seus pares de ofício. Evidenciando algumas peculiaridades de outros autores nacionais, para que não se cometa a generalização de enquadrá-los em bloco, o trabalho busca ressaltar as grandes áreas de atuação crítica, as “instâncias de legitimação” de Bourdieu. Nas últimas décadas, a crítica literária jornalística vem encontrando alguns impasses, principalmente em relação à velocidade do mercado editorial e da informação, em detrimento do espaço físico cada vez menor, impedindo a possibilidade de aprofundamento nos temas abordados. A partir do debate sobre as funções, características e dificuldades da atividade crítica, o presente trabalho busca apresentar algumas sugestões sobre a crítica literária baseado nas contribuições feitas por Otto Maria Carpeaux ao longo de sua atividade como crítico, intelectual público, historiador da literatura e jornalista. Sendo assim, buscar-se-á destacar as características fundamentais de Carpeaux em função de seu método, fornecendo perspectivas para uma leitura da literatura brasileira a partir de seus Ensaios Reunidos.The histories of criticism and literature are mixed over a given formation process and cultural development. However, the formation process of each one has its particularities. Therefore, the aim of this work, in tracing a brief trajectory of the history of Brazilian literary criticism, is to situate the critical activity of Brazilian author Otto Maria Carpeaux, contrasting him with his occupation peers. Evidencing some peculiarities of other national authors, in order not to commit the generalization to fit them as a single block, the work intends to emphasize the main areas of critical activity, the Bourdieu’s legitimation offices. In recent decades, the journalistic literary criticism has found some dead ends, especially for the speed of publishing and information, to the detriment of the over and over small physical space, hindering the possibility of to get deep into the discussed topics. From the debate about the functions, characteristics and difficulties of the criticism activity, the current study intends to introduce some suggestions upon the literary criticism based on the contributions done by Otto Maria Carpeaux along his activity as a critic, public intellectual, literature historian and journalist. Thus, it will intend to point the fundamental characteristics of Carpeaux in function of his method, providing some perspectives to read the Brazilian literature, according to his Collected Essays.Coordenação de Aperfeiçoamento de Pessoal de Nível Superio
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