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簡介:中文中文5500字出處出處INTERNATIONALJOURNALOFAGRONOMY,2012,2012畢業(yè)設計外文參考文獻譯文本畢業(yè)設計外文參考文獻譯文本譯文題目譯文題目IMPROVEMENTOFSOYBEANOILSOLVENTEXTRACTIONTHROUGHENZYMATICPRETREATMENT酶法提取大豆油的改進酶法提取大豆油的改進姓名學號號院(系)院(系)食品科學與工程學院食品科學與工程學院專業(yè)業(yè)食品科學與工程食品科學與工程指導老師指導老師最佳酶處理條件。每個實驗的PH,溫度和浸出時間等條件是根據(jù)含有3個變量的重要的復合實驗設計決定。這項設計由針對每個固體的20個實驗組成。表1展示了每個實驗的實驗條件。這項實驗設計是根據(jù)響應面分析法和包含有使回歸系數(shù)和軸向點最小的中心點反應建成的,因此可以獲得一個可重復的實驗設計。最小二乘法用來估算多項式近似值的參數(shù)。響應面的分析根據(jù)面設置提出來的。有效擴散實驗這項評估有效擴散的實驗使用餅和粕還有水解樣品以及程序描述過的所有物品來完成的。包含有2到3克樣品布制的管套被放置到錐形瓶中。加入500毫升的正己烷,攪拌液體介質(zhì)來消除外部阻力使轉移物聚集。每個實驗在25℃下完成,在T時段結束時含有樣品的套管從系統(tǒng)中被除去。這些實驗以5分鐘和10分鐘為間隔進行,知道1個小時的抽提完成。每一份樣品被泄油和干燥以消除溶劑和水分的蹤跡。此后,將稱量樣品放在裝有純正己烷的燒瓶中進行批量處理24小時。管套和樣品在烤箱中再次干燥以稱量不含有樣品。各批浸出物前后的重量差異被認為是除去T時段浸出的油分。固定床式柵欄浸出決定動力學的浸出物在柵欄中提取出來,在這個柵欄浸出器里,固定床是由大豆固體組成的。這個柵欄用這些預先稱量過的大豆固體裝滿。設定流量和溫度的正己烷從浸出器頂部加入。油水混合物樣品在浸出器出口獲得。全部浸出時間是60分鐘。1毫升小樣品在確定的時間點獲得。根據(jù)必須靈敏度,油水混合物中的油決定了分光光度計設置波長在280到300納米之間。系統(tǒng)中有效擴散系數(shù)的估計是依據(jù)國際農(nóng)學雜志上的菲克第二定律決定(由許多作者提出,包括CARRIIN和CRAPISTE)與下面的初始條件和邊界條件為無限完美攪動的散裝液體體積根據(jù)固體被認為是板和球,獲得了解決辦法1。考慮到所獲得的一系列快速收斂,以下是通過將每個解決方案集成,得到中厚板厚度2L球面半徑為因為目前在植物油中的甘油三酯有不同分子量和結構,很容易衡量油固體的質(zhì)量。因此,濃度比變成了21這兩個方程中的數(shù)量比例。方程3及4是線性化和根據(jù)時間T表示。兩條線的斜率用于評估有效的擴散系數(shù)。
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簡介:1中文中文3780字畢業(yè)論文外文資料翻譯學院生物科學與工程學院專業(yè)食品科學與工程姓名學號070301109外文出處JOURNALOFCHROMATOGRAPHYA,7641997177–182附件外文資料原文指導教師評語簽名年月日用外文寫2動注射分析的電化學檢測法(ECD法),使各種脂肪和油樣中游離脂肪酸的測定更加簡便快捷。因為脂肪酸含量可以由測量流動信號峰高和面積得出,該方法也適用于液相色譜電化學檢測法測定脂肪酸含量。高效液相色譜電化學檢測法被認定為一種不用衍生物檢測高級脂肪酸的簡便方法。2.實驗.實驗21.試劑棕櫚酸995、硬脂酸995、油酸99、亞油酸99,均購自和光試劑公司日本大阪。標準酸溶液都用乙醇乙腈1090混合溶液溶解。以下油樣都是從市場上購得山茶油資生堂牌,日本東京、玉米油和油菜籽油林時計化工,日本東京、橄欖油宮澤醫(yī)藥,日本東京,大豆油關東化學,日本東京。乙醇乙腈1090混合溶液和一個裝有6MM維生素K376MM高氯酸鋰的柱子分別作為流動相和醌溶液。電解液中的高氯酸鋰可以減少電化學電池的電阻。圖1高效液相系統(tǒng)流動相是乙醇乙腈混合溶劑,醌溶液為6MM維生素K76MM高氯酸鋰的乙醇乙腈溶液,DG是除氣裝置,P1、P2是泵,S是樣品注射器(20ΜL),分離柱(色譜柱100RP18,250MM4MM,5微米);MC是混合柱線圈(50厘米),D是電化學檢測器、電化學電池和電位儀,R是記錄儀。22儀器高效液相色譜電化學檢測系統(tǒng)如圖1所示,包括除氣器分光公司DG98050型,日本東京、泵P1和P2分光PU980型、樣品注射器羅丹尼7125型,美國加利福尼亞、結構性柱(ODS柱色譜柱100RP18,250MM34MM5MM,CICAMERCK公司,日本東京、電化學電池分光EC840型,電位儀皇氏電化學系統(tǒng)311B型,日本川崎、記錄儀分光807IT型。電化學電池由玻碳工作電極、飽和甘汞電極
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簡介:________________________________________這個項目是由中國自然科學基金贊助(NOS10110784,10110799與10175013)中文中文3295字在大氣條件下在部分電離等離子體層的高頻率的電磁在大氣條件下在部分電離等離子體層的高頻率的電磁波的功率吸收波的功率吸收郭斌,王曉鋼等離子體科學與工程中心的材料改性國家重點實驗室,大連理工大學物理系,大連,116024,中國摘要我們已經(jīng)研究了在大氣條件下,電磁波在金屬覆蓋的的非磁化等離子體層中的吸收,反射,和傳輸,而不是在前一次研究中發(fā)現(xiàn)的對等離子體層工作傳播電磁波的吸收,用常壓等離子體界面和金屬表面之間的無限時間思考出的等離子體層的吸收的總功率的一般公式被首次推導出。等離子體參數(shù)的影響,尤其是正離子組分的關系,對功率吸收過程中等離子體的負離子和電子也被拿來討論。結果表明負離子的存在大大降低了電磁波的功率吸收,電磁波的吸收也被計算出來了。關鍵詞電磁波;電磁波與等離子體的相互作用1介紹電磁波與等離子體的相互作用是等離子體物理學中一個重要問題12。近年來,電磁波在低溫等離子體中的傳播的研究吸引了越來越多的關注,因為其具有在大氣壓力排放中電磁波的吸收的潛在應用38。維德馬4發(fā)現(xiàn)冷碰撞等離子體中產(chǎn)生的氛圍壓力排放可以作為寬帶吸收;拉魯西等人5之后又相繼研究了在高等離子體的壓力大氣中微波的傳播;KORETZKY等人6最后證明了等離子體炬也能有效地吸收微波;劉7和唐8等人最近討論了在均勻磁化板等離子體模型中雷達波的吸收、反射和透射,這些文章主要集中于電子在吸收、反射和傳播的能力上的作用。很容易理解,當一個高頻電磁波在部分電離的等離子體中傳播時,是等離子體中的電子數(shù)量響應波激發(fā)高頻電子模式,然后這些模式中性氣體粒子背景下生成集體電子運動和電子中性粒子的碰撞去消散波能量。然而,在大氣環(huán)境中,總是存在一大部分氧氣分子,由于其高電負性,這些氧氣分子可以很容易地捕獲電子成為負離子。人們已經(jīng)發(fā)現(xiàn),在大氣條件下,帶負電荷的離子數(shù)量在負電荷中高達80,負離子的存在組分可以有力地降低等離子體中的電子數(shù)量并影響電磁波的傳播。在本文中,我們關注在垂直入射等離子體均勻板模型中負離子對電磁波的吸收、反射和傳輸?shù)挠绊憽1疚牡慕Y構如下在第二部分,主要介紹了一個模型和相應的分析公式,尤________________________________________這個項目是由中國自然科學基金贊助(NOS10110784,10110799與10175013)(6)????????VENVENVENJEE其中,分別是電子,積極和消極粒子的速度,從牛頓方程??VVV,,LE,),,對于帶電離子,由歐姆定律,LNEEVMJLL?????EEVMJN???????,我們有電導率的表達式,然后????????VENVENVENJEEEJ??????ORJ??1我們可以得出這樣的結論復雜的介電常數(shù)7???????????????????????????????????????22222222222222222211NNPNNPENENPENPNPENPERVVVVVVJVVV??????????????在以上的式子中,我們?nèi)菀椎贸觯?2/102EEPEMEN???2/12????MENOP??電中性區(qū)有NNEN。,2/12????????????MENOP??由于統(tǒng)一的等離子體的密度是常數(shù),在一定入射波,在沒有內(nèi)部反射的離子體中保R?持不變,在大氣等離子體界面Z0上,初始反射功率為8IIRRORPPP???????211其中,2是大氣等離子的反射比例,它也能反映出等1/1RR??????離子體與大氣的反射比例是對等的。等離子體的內(nèi)部,21/1???RR???電磁波的能量為92EXP12EXP2EXPZPZPPZPZPIORIT????????????如果金屬被認為是一種理想的導體,其表面是一個全反射界面,電磁波傳播回大氣等離子體界面,他的能量是
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上傳時間:2024-03-16
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大?。?0.12(MB)
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簡介:本科畢業(yè)論文外文文獻及譯文文獻、資料題目SOLIDIFICATIONOFGRAYCASTIRON文獻、資料來源SCRIPTAMATERIALIA文獻、資料發(fā)表(出版)日期20031019院(部)材料科學與工程學院專業(yè)材料成型及控制工程班級姓名學號指導教師翻譯日期2REVEALTHESOLIDIFICATIONMACROSTRUCTUREOFDI,COMBINEDWITHTHEUSEOFCOLORMETALLOGRAPHYTECHNIQUESTHATREVEALTHEMICROSEGREGATIONPATTERN,SHOWEDTHATTHEMACROSTRUCTUREOFDIISFORMEDBYRELATIVELYLARGEAUSTENITEGRAINS,THATCONTAINAVERYLARGENUMBERSOFGRAPHITENODULESTHISWASTHECASEFORHYPOEUTECTIC,EUTECTIC,ANDALSOHYPEREUTECTICDITHEOBJECTIVEOFTHISSTUDYISTOINVESTIGATETHESOLIDIFICATIONMECHANISMOFGIBYUSINGTHEMICROANDMACROSCOPICTECHNIQUES,SUCCESSFULLYAPPLIEDFORDIINEARLIERSTUDIESEXPERIMENTALMETHODS21MATERIALSTHEMELTSUTILIZEDINTHEPRESENTSTUDYWEREPRODUCEDBYUSINGA50KGMEDIUMFREQUENCYINDUCTIONMELTINGFURNACELOWMANGANESEPIGIRON,STEELSCRAPANDFERROALLOYSWEREUSEDASRAWMATERIALSMELTSWERECASTINRESINBONDEDSANDMOULDSTOPRODUCEROUNDBARSOF20,30AND46MMDIAMETERTABLE1LISTSTHECHEMICALCOMPOSITIONOFTHEALLOYSUSEDTHEMELTSWEREALLOYEDWITHCUANDNIINORDERTOPROVIDEENOUGHAUSTEMPERABILITYTOCARRYOUTTHEDAASMACROGRAPHYTECHNIQUE,WHICHISDESCRIBEDBELOW22MICROGRAPHICTECHNIQUETHECOLORETCHINGTECHNIQUEREVEALSTHESOLIDIFICATIONMICROSTRUCTURETHROUGHTHEUSEOFAREAGENTTHATBRINGSUPTHEMICROSEGREGATIONPATTERNSGENERATEDDURINGSOLIDIFICATION12THEETCHINGREAGENTISMADEOF10GNAOH,40GKOH,10GPICRICACIDAND50MLDISTILLEDWATERITMUSTBEPREPAREDANDHANDLEDWITHGREATCARE,SINCEITISCAUSTICANDTOXICETCHINGISCARRIEDOUTAT120℃278FFORABOUT2MINFIG1SCHEMATICILLUSTRATIONOFTHESOLIDIFICATIONUNITOFEUTECTICGI
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簡介:中文中文50005000字外文翻譯硼化物涂層的滑動和磨粒磨損行為(CMARTINI,GPALOMBARINI?,GPOLI,DPRANDSTRALLER)INSTITUTEOFMETALLURGY,UNIVERSITYOFBOLOGNA,VIALERISORGIMENTO4,BOLOGNA40136,ITALY摘要由FE2B單內(nèi)層和外層的FEB所構成的多相硼化物涂層對鐵和經(jīng)滲碳處理的中碳鋼有著深遠的影響。根據(jù)滑動和磨損試驗條件對樣本的硼摩擦學行為進行了研究。發(fā)現(xiàn)不同地區(qū)的涂料的磨損率有很大的不同。鐵硼化物晶體秩序解釋了這些差異的原因。薄,易碎的涂料層構成的無序晶體對兩種類型的抗磨損行為影響不大。然后,構成FE2B單緊湊,高度有序的晶體的地區(qū)阻力增加到最高值。耐干滑動樣本的硼優(yōu)于通過提交替代表面處理樣本資料(如氣體氮化)和含量較低的AWC鈷硬質(zhì)合金涂層。關鍵詞硼;鐵;鋼;滑動摩擦;磨粒摩擦;擇優(yōu)取向;晶體秩序;1導言日益增加的需求與令人滿意的電阻材料磨損與腐蝕性能促進了迅速擴張表面改性領域技術的發(fā)展。事實上,在許多應用中,這服務生活的組成部分是由表面特性所決定的。在這重要的熱化學處理的鋼種擴散的領域,如碳、氮和硼,硼處于一種特殊地位。一方面,即使在超過20個全球行動綱領,以及高耐磨性,經(jīng)熱化學處理的硼化物涂層涂料使普通鋼材有了很高的硬度。硼鋼構件在機械工程和汽車幾個摩擦學性能優(yōu)良的工業(yè)中有很廣泛的應用。值得注意的是,最好的結果是由粘固獲得,即工序使用含有粉末的混合物進行硼化組件(如碳化硼),活化劑(通常KBF4),并最終加入稀釋劑以控制潛在的硼化方法。然而,相對于氣相滲硼,粉末滲硼在工業(yè)生產(chǎn)過程中(一)比較復雜,費時和昂貴,(二)不適合過程控制和自動化,這種狀況妨礙了充分傳播滲硼處理工藝。努力加快工業(yè)氣體滲過程的進展,就雙方的加工條件和組成,硼化物層的孔隙度控制的主要問題加以解決,特別是,對等離子體及有關金屬表面的相互作用機制缺乏了解。比如,硼化物涂層制作了兩個中碳鋼等離子輔助化學氣相沉積法在?833K采用BCL3與H2混合氣體與AR稀釋,只有幾微米厚,這兩種滲硼層都很不好。另一方面,在汽車發(fā)動機的油泵驅(qū)動齒輪磨損性能的試驗中,一個類似混合氣體等離子體滲硼被發(fā)現(xiàn)與包滲硼相若。然而,獲得單相層需要滲硼熱處理,即涂層由含量較少但脆性不大的硼化物FE2B單鐵組成。試圖代替硼鹵化物和允許種植單一FE2B單相層高達10微米厚的一中碳鋼,任何進一步的發(fā)展有機前體乙硼烷硼體的方法正由滲碳的不利因素所影響。僅由未經(jīng)處理的樣品對這些硼化物層的摩擦學性能進行了評價。在摩擦學行為上已經(jīng)做了很多工作,特別是在非常不同的測試條件研究不同組成硼對材料的顯微硬度進行了測量?;瑒訔l件下的比較試驗,中碳鋼,也是在570攝氏度氮化氣體(總深度處理鈭毫米)或10微米的硬鉻涂層(硬度6768HRC)的厚層。一個M35工具鋼(成分C08%,鉻375%,鉬50%之間,610%,第五205%,鈷50%),其硬金屬層涂布(硬質(zhì)合金有限公司18%,硬度?88HRA)存放于空氣等離子噴涂(APS)的技術,被選作參考,高耐磨材料。22摩擦學測試干滑動進行了測試,采用計算機控制滑塊上缸摩擦計(圖1)。固定滑桿由研究中的材料在(5毫米5毫米50毫米)棱柱形式構成。該構件材料是氧化鋁陶瓷涂層的組成(重量比87%)和二氧化鈦(洛氏硬度60,表面粗糙度RA05微米),沉積在旋轉圓筒。這些測試下進行了5和25N和外加負載,滑動速度018MS1,滑動距離達5公里,在室溫下(2025?C)和在實驗室的空氣,(在相對濕度范圍5060%)。雙方摩擦磨損性和制度(即兩個滑塊和氣缸磨損累計)的連續(xù)測量了一彎曲載荷單元的手段和位移傳感器,分別被作為滑動距離函數(shù)記錄。在每個測試結束時,磨痕深度為兩滑塊和氣缸測量了表面輪廓的方法(傳感器曲率半徑,5微米),垂直記錄線配置的磨痕。采用微型磨損試驗機(流動衛(wèi)星通信系統(tǒng))對硼化物的涂層耐磨損進行了評估,它是基于縮孔幾何效應。球的反轉,在小磨料粒子的存在扁試樣旋轉產(chǎn)生一種強加在材料球面幾何磨損隕石坑?;旧习ㄣ@機,如圖2所示,馬氏體鋼硬球,(半徑為R127毫米,硬度HV1000)對下研磨漿的調(diào)查樣本輪換的存在(SIC水懸浮顆粒濃度的初步規(guī)模45微米,075克厘米3),維護和地區(qū)的聯(lián)系,通過一個緩慢的補充不斷滴飼料(?025立方厘米分鐘1)。圖2示意圖球縮孔微量磨損試驗機
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上傳時間:2024-03-12
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簡介:中文中文2935字出處出處HAOJ,TANGX,LIW,ETALFIRSTPRINCIPLECALCULATIONSOFHIGHPRESSUREPHASETRANSFORMATIONSINRUCJEPL,2014,1054107110本科畢業(yè)設計(論文)外文翻譯譯文本科畢業(yè)設計(論文)外文翻譯譯文學生姓名學生姓名院(系)(系)材料科學與工程專業(yè)班級專業(yè)班級材料1101指導教師指導教師完成日期完成日期2015年3月1日PAW)13法,平面波的動能截止520EV。表1RUC的ZB型,型,WC型和型和I4MM結構在選定壓力下的結構參數(shù)結構在選定壓力下的結構參數(shù)結構類型壓力(GPA)晶格參數(shù)A體積原子坐標ZB型0A46024545A,4566B24367RU4A0,0,0C4C1/4,1/4,1/40A2854C535621818RU2A0,0,0C2A0,0,0628I4MM10A2829C527921818RU2A0,0,0C2A0,0,06260A29632908C,2921AC27012822C,2672A20531RU1A0,0,0C1F2/3,1/3,1/2WC型30A2875C265220531使用分辨率為2Π003的MONKHORST包布里淵區(qū)采樣網(wǎng)格,導致總能量的收斂。A1比1兆電子伏/原子更好。采用密度比2Π002更密的網(wǎng)格,通過應力應變方法計。A1算了彈性常數(shù)14。聲子色散曲線使用PHONOPY程序計算15,這是一個基于超晶胞方法計算聲子的開源軟件包16。這種方法通過VASP代碼優(yōu)化超晶胞,使用費曼海爾曼定理計算獲得的能量。在所有三個階段我們都使用333超晶胞(27RUC式的單元)。結果和討論經(jīng)過充分幾何優(yōu)化,ZB型和WC型結構保持其最初的對稱性,如圖1。在ZB型結構中,每個的RU(C)原子鍵合有4個C(RU)原子,常壓下RUC鍵的長度是198。在WC型結構中,每個RU(C)原子被六個C(RU)原子包圍,。A常壓下有相對較長的RUC鍵,長度為2179。在表1中,B型和WC型相結構參。A數(shù)與現(xiàn)有的實驗數(shù)據(jù)6以及早期的理論結果比較8,9,在2的區(qū)間內(nèi)發(fā)現(xiàn)一個很好的結論。PMN2型RUC的結構參數(shù)和原子位置子在特定壓力下也完全優(yōu)化。然而,我們驚奇1地發(fā)現(xiàn),PMN2型的對稱性會在優(yōu)化期間發(fā)生變化。在OSC的PMN2結構中10,每11個OS原子與五個C原子相協(xié)調(diào),形成扭曲的OSC金字塔。在每個OSC金字塔55中,四個底部OSC鍵可以分為兩種鍵長度略有不同的類型,如圖1所示。在研究的
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上傳時間:2024-03-16
頁數(shù): 10
大?。?1.05(MB)
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簡介:1中文中文5200字本科畢業(yè)設計本科畢業(yè)設計論文論文外文外文文獻翻譯文獻翻譯學院院化學與材料工程學院附件件1外文資料翻譯譯文;2外文原文31引言聚合物共混被廣泛用于開發(fā)新材料,要表現(xiàn)出良好的性能,取決于混合物成分的選擇。由于大多數(shù)聚合物共聚,它們的混合物具有能形成各種多相協(xié)同作用的性質(zhì)。在處理過程中聚合物組成的結構取決于多種因素,如聚合物材料的性能(界面張力,流變性能),加工條件(剪切速率,攪拌時間)和使用材料的相對含量。聚合物形態(tài)類型在很大程度上決定物理共混物的性能,從而可以適當控制達到理想的形態(tài)特性,在共混物的誘導作用中起關鍵作用。液滴/矩陣形態(tài)對于其它機械性能賦予有利的影響,所以高抗沖聚苯乙烯、聚丙烯,已被廣泛研究。共連續(xù)結構也已經(jīng)引起了業(yè)界的廣泛的關注,因為它們有潛力,可以擴大應用范圍。聚合物共混由于其相互關聯(lián)的性質(zhì),所以共連續(xù)形態(tài)在導電性或滲透性兩個階段由于滲流而表現(xiàn)出很有趣的特性。在文獻中廣泛采用包括溶劑萃取法,顯微鏡和流變來確定共連續(xù)性形態(tài)和由此產(chǎn)生的結構。在過去十年中,廣泛的研究已經(jīng)證實納米對聚合物結構有影響?,F(xiàn)在人們普遍接受在有納米粒子的存在下,如有機黏土和納米二氧化硅,液滴矩陣分散階段的形態(tài)轉移向更細的分散。納米填料的階段通常選擇性定位矩陣或相間,似乎是解釋這一現(xiàn)象的關鍵。已提供可能的解釋包括由于填料吸附在兩相接口的增容作用可以在兩種聚合物中降低界面張力。然而,當填充駐留在矩陣時,這些機制顯然不占優(yōu)勢。在這種情況下,可能是由于粘土粒子和納米粒子分散良好的原因,另一方面,有相當多的報道稱納米填料在各種混合組合中很少有利于形成共連續(xù)結構。在某些情況下的導電填料,如碳碳納米管分散在共同連續(xù)的階段,是可行的,因為它對增加導電性能有利。由此可見,除了納米填料的物理性質(zhì),化學性質(zhì)上有明顯效果的共混物,通過其結構的控制,它們也可以產(chǎn)生更多的間接影響。用納米二氧化硅對聚丙烯和聚烯烴彈性體(POES)的熱塑性影響進行了調(diào)查,在PP基體中的納米二氧化硅選擇性分散。這種方法已被證明可以改良PP基體剛度,同時也能保持柔順性。此外,結果表明,當納米二氧化硅定位在PP基體時,這些混合物的液滴矩陣形態(tài)更細。目前的工作重點在納米二氧化硅對共連續(xù)PP/POE共混體系組成和結構的影響。眾所周知,結構上的變化可以影響共混物的物理性能。
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上傳時間:2024-05-21
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簡介:第1頁共15頁3490單詞,單詞,18000英文字符,英文字符,6100漢字漢字出處出處IRISHJD,PAULW,SHAUMEYERJN,ETALTHENEXTGENERATIONOCEANOBSERVINGBUOYINSUPPORTOFNASASEARTHSCIENCEENTERPRISEJSEATECHNOLOGY,1999,403743譯文支持美國航天局地球科學事業(yè)的下一代海洋觀測浮標簡介伍茲霍爾海洋研究所與杰克遜和圖爾正在開發(fā)一款改良版的支持美國航天局地球科學事業(yè)的系船測定浮標系統(tǒng)。此項新型設計運用了伍茲霍爾海洋研究所在浮標、系泊、傳感系統(tǒng)方面的海洋經(jīng)驗,并結合了杰克遜和圖爾在航空遙測和計算機系統(tǒng)方面的專長。浮標系統(tǒng)包括一整套氣象傳感器、水溫、傳導性(鹽度)、生物光學傳感器和輻射計在不同深度的性能,以及應用于海流的聲學多普勒海流剖面儀。此系統(tǒng)可以對海洋科學研究在全世界范圍內(nèi)的陸架區(qū)域進行部署調(diào)配,包括海洋水色衛(wèi)星地面真實性驗證。它將新一代近地軌道通信衛(wèi)星(LEO)應用于兩方面,高通量指揮控制和數(shù)據(jù)遙測。1浮標結構這些美國航空局浮標系統(tǒng)由鋼和一個鋁制的泡沫浮圈制成。鋼,用于低成本和簡單的結構建造,它們被熱鍍鋅,并且為了防止腐蝕而被涂層。一些舊的鋼護浮標(潛水式有塔狀物的網(wǎng)狀浮子)在20年后仍然還在使用,所以其使用壽命不是問題。而且,基底用重鋼棒線材制成可以減少同鋁制浮標一樣必須要增加鋅制或鉛制重物來進行壓載。浮標塔由6061T6鋁材制成,因為這種材料輕,塑料墊圈可以使鋼基底與電隔離。安裝在塔上的有一個雷達反射器、閃光燈式海洋監(jiān)視巡防、遙測天線、氣象傳感器、太陽能電池板和一個阿爾戈斯定位信標天線。太陽能電板可以通過擺動從而進入到浮標中心的儀表井。這個井直徑24”深45”為電池、太陽能電池板調(diào)節(jié)器、電力輸送系統(tǒng)、數(shù)據(jù)處理和儲存系統(tǒng)、遙測系統(tǒng)和后備阿爾戈斯定位信標提供了足夠的空間??梢詮钠漤敳康囊粋€開口進入到浮標的水密電子井。較大直徑可以允許一個人側身進入到井中以對其底部的電池進行作業(yè)。為了簡易維修而裝配電子器件一直以來都是一個問題。在類似但是較小的GLOBEC(GLOBEC)浮標中,電池和電子器件被擰在電子井每一面的欄桿上。俯身在小井中對這些器件進行作業(yè)的確很困難。在這個新型的浮標中,電子器件安裝在支架上,支架可以由焊接在井內(nèi)部的四個分開的導管進行滑動。每個導管頂部的硬橡膠“彈簧”和銷釘將支架固定住。將電子器件和電池從浮標中拿出進行外部維修仍舊是個難題。第3頁共15頁時進行定期上漆著色。3.太陽能發(fā)電系統(tǒng)太陽能發(fā)電系統(tǒng)浮標數(shù)據(jù),遙感系統(tǒng)和傳感器均由太陽能發(fā)電系統(tǒng)提供動力。四個SOLAREX64瓦特太能能電池板通過專業(yè)概念公司生產(chǎn)的分路開關調(diào)節(jié)器來裝載兩個CONCORD電池公司生產(chǎn)的安時可充電密封膠體干電池。二極管網(wǎng)絡將電池連接到數(shù)據(jù)系統(tǒng)和傳感器以防因放電導致一部分系統(tǒng)的癱瘓。所以,兩個單獨的電力系統(tǒng)有一塊電池和兩個太陽能電池板,每個太陽能電池板為浮標系統(tǒng)提供動力。這種冗余在過去并未有證明其是必要的,但是增加了可靠性。早期浮標的太陽能發(fā)電系統(tǒng)使用了四種10瓦特裝有兩個40安時POWERSONIC膠體干電池的SOLAREX電池板。這種配置在緬因灣和馬薩諸塞灣相當適用。GLOBEC科學浮標使用四個20瓦特SOLAREX或西門子電池板以安裝三個POWERSONIC40安時膠體干電池。GLOBEC防護浮標使用兩個10瓦特SOLAREX電池板以安裝一個單40安時膠體干電池。實踐證明這些系統(tǒng)可靠有效,除了設備故障引起強流流失,并為設備提供令人滿意的動力。我們使用10瓦特SOLAREX電池板15年之久,而且至今它們看來仍嶄新如昨仍在有效工作。早期鋼浮標太陽能電池板安裝在近水45°角度處。設計理念是讓波浪可以沖洗掉因鳥兒停留在浮標上對太陽能電池板產(chǎn)生的臟污。對于額外電力的要求可以通過添加安裝高于塔的太陽能電池板來實現(xiàn),而且它們沒有觀察不到的臟污。所以,GLOBEC太陽能電池板安裝在如建議的用于地面應用的緯度正10°之處。在測試中顯示水中光的反射使得這個角度未有像之前想象的那么重要。新浮標中的配置使得電池板與塔稍微調(diào)整具有一定角度,電池板受到塔端的圓圈和塔底的SURLYN泡沫浮標保護。我們還沒有遇到過太陽能電池板破損的現(xiàn)象除了在恢復時它受到船只突出部分的撞擊(在使用浮標的10年中有2塊電池板損壞)。太陽能電池板陣列傳輸電力給電池系統(tǒng),然后電池系統(tǒng)傳送電力到浮標系統(tǒng),這一過程是很難計算的。包圍在浮標周圍的四個電池板確保至少有一塊電池板受到太陽的直射,至少一塊在陰暗處。若在上午晴朗無云的天氣條件下,太陽與一塊電板平齊,這塊電池板傳送35安培電至一塊膠體干電池中。電池板制造商在電池板的說明書上標明了最大極限裝載電流為37安培,所以我們做的不算太過分。與太陽成90°角的兩塊電池板每塊提供10安培電流,在陰暗處的電池板提供075安培。所以,“256瓦特”太陽能電池板陣列實際上可以給電池供給80瓦特電力。那時候,太陽能電池板傳送42安時(約550瓦小時)到電池中。這些數(shù)據(jù)需要通過太陽角度和白晝時間來進行核算。同時,在較冷天氣下,太陽能電池板和電池會表現(xiàn)出較低的效率。調(diào)節(jié)器對防止膠體干電池的過量充電非常必要。如果充電過量它們會釋放氫氣,在浮標井中會形成一個易爆炸的環(huán)境。我們也安裝了一個催化室將氫氣和浮標中的所有氧氣轉化為水,水最終由干燥劑吸收掉。在電池上有一個穿過阻流二極管的電壓降,這樣儀表上顯示的能量僅移動了低于電池電壓的1/3伏。溫度不足和電池效能低的原因是我們通常設計電力系統(tǒng)的兩個安全因素的其中之一,并且系統(tǒng)已提供了必要的電力。
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簡介:1推進土壤科學朝著前沿的地球科學發(fā)展姓名杜巖學號M110792課程名稱高級土壤學考試形式文獻翻譯與綜述文獻作者LARRYPWILDINGA,HENRYLINB雜志GEODERMA,2006,257274摘要土壤科學的發(fā)展遠景、方向和土壤科學的形象正在發(fā)生變化。從歷史上看,土壤科學的演變經(jīng)歷一個迂回曲折的道路,從當初作為地質(zhì)學最基礎的學科,到開始應用于農(nóng)業(yè)和環(huán)境保護的準則,至現(xiàn)在發(fā)展成為用于地球關鍵帶區(qū)域調(diào)查的生物地質(zhì)科學。如此終止了土壤學發(fā)展道路上的循環(huán)般的曲折命運,而且一路走來,土壤科學變得更加完善、應用更廣泛、綜合性更強、分析能力和定量性更高。盡管本文中描述了土壤科學面臨的挑戰(zhàn),但是現(xiàn)在對于土壤科學來說卻是一個黃金時期去更加緊密地將其專業(yè)知識與其他生物和地理科學更加緊密的融合。這將不僅可以顯著增加獲取校外資金和公眾的支持機會而且可以獲得土壤科學進步。因此,土壤科學需要大力成為更具互動性的科學和拓展延伸它所扮演的角色,從而超越傳統(tǒng)的農(nóng)業(yè)。空間土壤多樣性與景觀動態(tài)變化的專業(yè)知識對于這項投資成功來說是根本性的關鍵。土壤學作為土壤科學的一個獨特的分支學科,所作出的貢獻可與地球科學相當,包括,例如澄清地道域的可變性、表層風化過程、地球系統(tǒng)動力學和滲流區(qū)的流向與運輸過程。伴隨著生物地球科學盛況,水文土壤學是在這個多學科、跨學科時代及時增加的學科,系統(tǒng)方法用于發(fā)展科學的綜合性優(yōu)先級以及應用在地球科學上。相比于其他生物和地理科學,水文土壤學今年三月份在處理全球性地球科學的優(yōu)先次序方面有一個利基。土壤科學家支持改變模式并且青睞于與生物和地理科學社會的更密切聯(lián)系。在這方面,水文土壤學發(fā)揮獨特的作用。關鍵詞關鍵帶區(qū)域;地球科學;土壤圈;水文土壤學;土壤學;土壤結構;土壤功能1、簡介土壤是位于地球陸地表層提供生命支持的寶貴的、多樣和脆弱的自然資源。雖然它眾所周知的的作用是提供養(yǎng)分和水分來維持農(nóng)業(yè)生產(chǎn)和生態(tài)系統(tǒng),土壤資源也同樣有一些基本的功能,如廢物處置、地下水補給、影響氣候和作為工程建筑、制造業(yè)的原材料。通常來說,這種具有生物活性、結構多孔的介質(zhì)就是所謂的土壤圈,具有調(diào)解土層中的大部分生物地球物理和化學的之間的相互作用,還有地表水和地下水的平衡問題,更甚參與大氣層的調(diào)節(jié)。例如有機碳可以通過土壤返還給大氣層,大氣中約25%含量的二氧化碳來自土壤層中的生物氧化反應,其中包含了從大氣中吸收的兩倍多的碳和比所有植被高達三倍的的碳(NRC,2001;DREES等,2001;拉爾,2001年,2004年)。土壤同時對水文循環(huán)也有重大影響。大多數(shù)人使用的水來自地下水、溪流與湖泊,不管其來源途徑,水的質(zhì)量和數(shù)量在很大程度上是由它通過的土壤的性質(zhì)來決定的。在大多數(shù)國家,土壤科學領域主要作為農(nóng)業(yè)產(chǎn)品研究開發(fā)的副產(chǎn)品。在美3行為以及進程。它包括土壤質(zhì)量、分布、范圍、空間的多樣性和利用,還有土壤景觀結構從微觀到宏觀上的管理,但是也不僅僅限于這些(SUMNER,2000年)。它還涉及到生態(tài)系統(tǒng)中的可再生自然資源或著人類改造后的土壤的緩慢恢復。土圖1關于地球關鍵帶與土壤圈的示意圖土壤圈是地球表面一層很薄的土壤,如一個復合土工膜跨過水與溶質(zhì)以及能源、氣體、固體與生物體,主動與大氣、生物圈、水圈和巖石圈進行交換,去創(chuàng)造一個維持生命的環(huán)境。土壤與水的相互作用為生物與非生物之間創(chuàng)造了一個基礎界面,因此它決定了地球系統(tǒng)與它關鍵帶的狀態(tài)(圖形未按比例繪制)(在LIN之后修飾,2005)。壤學認為那些近地表的過程決定了土壤圈與演化、環(huán)境地球化學和生物體的棲息地聯(lián)系的質(zhì)量與功能。它為地球系統(tǒng)的各個系統(tǒng)的組合提供了幫助工具,以便了解時間和空間多樣性的成因與后果,和提供一個更加全面的方法來實現(xiàn)生態(tài)系統(tǒng)的有效的動態(tài)過程。這門科學的目前范圍應該是多方面的,分別作為農(nóng)藝學、環(huán)境學、生態(tài)學以及作為一個生物和地球科學。這后來的機遇對土壤科學來說,它不能很好被把握,而且地球科學的社會人士通常對它的了解不多。土壤科學是生物和地球科學的合作伙伴,為土壤圈和關鍵帶新的增長潛力的調(diào)查提供主要途徑。水文土壤學是土壤科學和水文學的交叉學科,涵蓋多學科與多尺度,用來研究地球關鍵帶的土壤學和水文學互動的過程LIN,2003。它也可以被視為土壤科學和地球科學的一個分支學科,用來調(diào)查景觀設置中成土過程與空間多樣性通過土壤圈的氣體和液體流量。LIN等(2005)最近對一個水文土壤學在生物和地球科學的多尺度及其與對地球關鍵帶的綜合性研究方面的銜接中扮演的
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簡介:EFFECTOFNANOSILICAONTHECOCONTINUOUSMORPHOLOGYOFPOLYPROPYLENE/POLYOLEFINELASTOMERBLENDSSHLEEA,MKONTOPOULOUA,,CBPARKBADEPARTMENTOFCHEMICALENGINEERING,QUEEN’SUNIVERSITY,KINGSTON,ONK7L3N6,CANADABDEPARTMENTOFMECHANICALANDINDUSTRIALENGINEERING,UNIVERSITYOFTORONTO,TORONTO,ONM5S3G8,CANADAARTICLEINFOARTICLEHISTORYRECEIVED25OCTOBER2009RECEIVEDINREVISEDFORM8JANUARY2010ACCEPTED11JANUARY2010AVAILABLEONLINE18JANUARY2010KEYWORDSNANOCOMPOSITESTHERMOPLASTICOLEFINBLENDSCOCONTINUOUSMORPHOLOGYABSTRACTTHISPAPERREPORTSTHEEFFECTOFNANOSILICASIO2ONTHEMORPHOLOGYOFCOCONTINUOUSIMMISCIBLEPOLYPROPYLENEPP/POLYOLEFINELASTOMERPOEBLENDSTHEUNFILLEDBLENDSDISPLAYPHASEINVERSIONANDACOCONTINUOUSSTRUCTUREATARATIOOF50/50PP/POEBYWEIGHTUPONADDITIONOFSIO2INTHEPRESENCEOFMALEATEDPPCOMPATIBILIZERAFINERSTRUCTURE,CONSISTINGOFELONGATEDPOEPARTICLESDISPERSEDWITHINTHEPPPHASEISOBTAINEDTHISTRANSFORMATIONISASSOCIATEDTOTHEPRESENCEOFFINELYDISPERSEDSIO2PARTICLESTHATARELOCALIZEDEXCLUSIVELYWITHINTHEPPMATRIXTHEIMPACTPROPERTIES,FLEXURALANDYOUNG’SMODULIOFTHEBLENDSINCREASESIGNIFICANTLY,POINTINGTOASYNERGISTICEFFECTARISINGFROMTHEPRESENCEOFTHEREINFORCEDPPPHASE,CONTAININGHIGHAMOUNTSOFTHEFINELYDISPERSEDELASTOMERICPHASE?2010ELSEVIERLTDALLRIGHTSRESERVED1INTRODUCTIONPOLYMERBLENDINGISUSEDEXTENSIVELYTODEVELOPNEWMATERIALSTHATEXHIBITAFAVORABLECOMBINATIONOFPROPERTIES,DEPENDINGONTHESELECTIONOFBLENDCOMPONENTSASMOSTPOLYMERSAREIMMISCIBLE,THEIRBLENDSFORMMULTIPHASESYSTEMSWITHVARIOUSMORPHOLOGIESANDSYNERGISTICPROPERTIESTHENATUREOFTHESTRUCTURESCREATEDDURINGPROCESSINGDEPENDSUPONSEVERALFACTORS,SUCHASTHEMATERIALPROPERTIESOFTHENEATPOLYMERSINTERFACIALTENSION,RHEOLOGICALPROPERTIES,PROCESSINGCONDITIONSSHEARRATEANDMIXINGTIMEANDTHERELATIVEAMOUNTSOFMATERIALUSEDTHETYPEOFMORPHOLOGYDETERMINESTOALARGEEXTENTTHEPHYSICALPROPERTIESOFTHEBLENDS,THUSPROPERCONTROLOFTHEMORPHOLOGYPLAYSAKEYROLEININDUCINGDESIRABLEPROPERTIESTOTHEBLENDSTHEDROPLET/MATRIXMORPHOLOGY,WHICHIMPARTSFAVORABLEIMPACTANDOTHERMECHANICALPROPERTIES,ASINTHECASEOFHIGHIMPACTPOLYSTYRENEANDPOLYPROPYLENE,HASBEENWIDELYSTUDIEDCOCONTINUOUSMORPHOLOGIESHAVEALSODRAWNSIGNIFICANTINTEREST1,BECAUSETHEYHAVETHEPOTENTIALTOWIDENTHEAPPLICATIONRANGEFORPOLYMERBLENDSDUETOTHEIRINTERCONNECTEDNATURE1–4COCONTINUOUSMORPHOLOGIESEXHIBITINTERESTINGPROPERTIESRELEVANTTOCONDUCTIVITYORPERMEABILITYOWINGTOTHEPERCOLATIONOFTHETWOPHASESAWIDERANGEOFTECHNIQUESTODETERMINETHECOCONTINUITYREGIONANDTHERESULTINGSTRUCTURES,INCLUDINGSOLVENTEXTRACTION5–9,MICROSCOPY10–14ANDRHEOLOGY10,15–17HAVEBEENDESCRIBEDINTHELITERATUREEXTENSIVERESEARCHDURINGTHELASTDECADEHASCONFIRMEDTHEINFLUENCEOFNANOPARTICLEADDITIONONTHEMORPHOLOGYOFPOLYMERBLENDSITISNOWWIDELYACCEPTEDTHATINTHEPRESENCEOFNANOPARTICLES,SUCHASORGANOCLAYSANDNANOSILICA,THEDROPLETMATRIXMORPHOLOGYSHIFTSTOWARDAFINERDISPERSIONOFTHEMINORPHASETHESELECTIVELOCALIZATIONOFTHENANOFILLERINONEOFTHEPHASES,TYPICALLYTHEMATRIXORTHEINTERPHASE,SEEMSTOBEKEYTOEXPLAININGTHISPHENOMENONPOSSIBLEEXPLANATIONSTHATHAVEBEENOFFEREDINCLUDECOMPATIBILIZINGEFFECTSDUETOFILLERADSORPTIONATTHEINTERFACEOFTHETWOPOLYMERS,RESULTINGINAREDUCTIONINTHEINTERFACIALTENSION18–20HOWEVERTHESEMECHANISMSAREOBVIOUSLYNOTDOMINANTWHENTHEFILLERRESIDESINTHEMATRIX21INTHATCASEITHASBEENSPECULATEDTHATEXFOLIATEDCLAYPLATELETSORWELLDISPERSEDNANOPARTICLESSURROUNDEDBYANIMMOBILIZEDBOUNDLAYEROFPOLYMERMAYHINDERPARTICLECOALESCENCEBYACTINGASPHYSICALBARRIERS22–24ONTHEOTHERHAND,THEREAREQUITEAFEWREPORTSOFNANOFILLERSFAVORINGTHEFORMATIONOFCOCONTINUOUSSTRUCTURESINVARIOUSBLENDCOMBINATIONS25–30INSOMECASES,THEFORMATIONOFADOUBLEPERCOLATEDSTRUCTURE,WHERECONDUCTIVEFILLERSSUCHASCARBONNANOTUBESAREDISPERSEDINONEOFTHECOCONTINUOUSPHASESISDESIRABLEANDISDONEONPURPOSE,SINCEITCANRESULTINFAVORABLECONDUCTIVEPROPERTIES31,32ITISTHEREFORECLEARTHAT,APARTFROMTHEOBVIOUSEFFECTTHATNANOFILLERSHAVEONTHEPHYSICALPROPERTIESOFTHEBLENDS,THEYCANALSOGENERATEAMOREINDIRECTEFFECT,THROUGHTHECONTROLOFTHEIRMORPHOLOGYCORRESPONDINGAUTHORTELT16135333079FAXT16135336637EMAILADDRESSMARIANNAKONTOPOULOUCHEEQUEENSUCAMKONTOPOULOUCONTENTSLISTSAVAILABLEATSCIENCEDIRECTPOLYMERJOURNALHOMEPAGEWWWELSEVIERCOM/LOCATE/POLYMER00323861/–SEEFRONTMATTER?2010ELSEVIERLTDALLRIGHTSRESERVEDDOI101016/JPOLYMER201001018POLYMER5120101147–1155FOURBLOCKSOFKNEADINGDISCSHAVINGPOSITIVET30?,NEUTRAL90?,ANDNEGATIVE?30?STAGGEREDANGLESANDTWOLEFTHANDEDSCREWELEMENTS,TOPROVIDEGOODDISPERSIVEANDDISTRIBUTIVEMIXINGTHESCREWSPEEDWAS200RPM,RESULTINGINANEXTRUSIONRATEOF25KG/HTHETEMPERATUREPROFILEINTHEEXTRUDERFROMTHEFEEDINGSECTIONTOTHEDIEWAS60?C–200?C–205?C–205?C–210?C–210?C–200?CFORALLBLENDSTHESECONDITIONSWERESELECTEDBECAUSEPRIORWORKHASSHOWNTHATTHEYPROVIDETHEOPTIMUMDISPERSIONOFNANOSILICASILICAWASADDEDTOTHE50/50PP/POEBLENDSATLOADINGSRANGINGFROM1TO5WTPPGMANWASUSEDTOIMPROVETHEDISPERSIONOFSIO2RESULTINGINAPPMATRIXCOMPOSITIONOFPP/PPGMAN90/10ANTIOXIDANT03PHRWASADDEDTOALLFORMULATIONS23MECHANICALPROPERTIESTENSILEPROPERTIESWEREMEASUREDUSINGANINSTRON3369UNIVERSALTESTER,ATCROSSHEADSPEEDSOF50MM/MINDUMBBELLSHAPEDSPECIMENSWERECUTWITHATYPEVDIEACCORDINGTOASTMD638FROM15MMTHICKSHEETS,WHICHWEREPREPAREDBYCOMPRESSIONMOLDINGOFTHECOMPOUNDEDSAMPLESATAPP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上傳時間:2024-03-13
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簡介:JOURNALOFCHROMATOGRAPHYA,7641997177–182DETERMINATIONOFHIGHERFATTYACIDSINOILSBYHIGHPERFORMANCELIQUIDCHROMATOGRAPHYWITHELECTROCHEMICALDETECTIONTFUSE,FKUSU,KTAKAMURASCHOOLOFPHARMACY,TOKYOUNIVERSITYOFPHARMACYANDLIFESCIENCE14321,HORINOUCHI,HACHIOJI,TOKYO19203,JAPANRECEIVED15APRIL1996REVISED15AUGUST1996ACCEPTED22OCTOBER1996ABSTRACTASYSTEMOFHIGHPERFORMANCELIQUIDCHROMATOGRAPHYWITHELECTROCHEMICALDETECTIONWASDEVELOPEDFORTHESEPARATIONANDDETERMINATIONOFHIGHERFATTYACIDSANOCTADECYLSILICAODSCOLUMNWASUSEDASTHESTATIONARYPHASEANDANETHANOL–ACETONITRILE1090MIXTUREASTHEMOBILEPHASETHEELUATEWASMIXEDWITHAQUINONESOLUTIONWHICHWASCOMPOSEDOF6MM2METHYL1,4NAPHTHOQUINONEAND76MMLICLOINETHANOL–ACETONITRILE1090THROUGHAMIXINGCOILPEAKHEIGHTFOR4HIGHERFATTYACIDSMEASUREDAT2415MVVSSATURATEDCALOMELELECTRODESCEWASLINEARAGAINSTTHEAMOUNTOFACIDBETWEEN20AND1200PMOLFREEFATTYACIDSINVARIOUSOILSAMPLESWEREDETERMINEDBYTHISMETHOD,WHICHWASFOUNDNOTONLYSENSITIVEANDREPRODUCIBLEBUTALSOASIMPLEMEANSFORSEPARATINGANDDETERMININGFREEFATTYACIDSINOILSKEYWORDSELECTROCHEMICALDETECTIONFATTYACIDS1INTRODUCTIONPHOREPRIORTHECOLUMNSEPARATIONISREQUIREDFORSENSITIVEDETECTIONINHPLCMANYDERIVATIZINGMANYATTEMPTSHAVEBEENMADEFORTHESEPARATIONLABELLINGREAGENTSHAVEBEENDEVELOPEDFORTHISANDDETERMINATIONOFFATTYACIDSBYGASCHROMATOGPURPOSE4–13ACATALYSTINSOMECASESISREQUIREDRAPHYGC1–3ANDHIGHPERFORMANCELIQUIDCHROFORCOMPLETEDERIVATIZATIONOWINGTOTHEPOORREACMATOGRAPHYHPLC4–13INCURRENTGCANALYSISTIVITYOFCARBOXYLGROUPS4FORTHEDERIVATIZATIONCOMMONLYEMPLOYEDTODAY,FREEFATTYACIDSAREOFFATTYACIDSWITHSUCHREAGENTS,THEAMOUNTOFGENERALLYCONVERTEDTOTHEIRMETHYLESTERSANDTHENREAGENT,REACTIONTEMPERATUREANDTIMEARECRITICALFORINJECTEDINTOACAPILLARYGCMETHYLATIONANDGCHIGHREACTIONEFFICIENCYANDAVOIDINGANYSIDEPRODCONDITIONS,SUCHASPROGRAMMEDTEMPERATURE,SPLITUCTFORMATIONWATERISOFTENANINCOMPATIBLEENINJECTION,ASWELLASTYPEOFCAPILLARYCOLUMN,CARRIERVIRONMENTFORDERIVATIZATIONREACTIONSANDTOFINDAGAS,ANDDETECTOR,AREALLIMPORTANTDETERMINANTSOFSOLUTIONTOTHISPROBLEM,EXAMINATIONWASMADEOFHIGHACCURACYANDPRECISIONTHEMAINADVANTAGEOFTHEUSEOFAQUEOUSMICELLARSYSTEMSFORDERIVATIZAHPLCWITHFLUORESCENTDETECTIONHPLCFLOFFATTYTION5ALTHOUGHFLUORIMETRICDETECTIONISQUITEACIDSISHIGHSENSITIVITYHOWEVER,OWINGTOTHEWEAKSENSITIVE,FLUORESCENTINTENSITYISLIABLETOVARYOWINGABSORPTIONANDFLUORESCENTPROPERTIESOFFATTYACIDS,TOTHEPRESENCEOFSUBSTANCESINCOMPLICATEDSAMPLESDERIVATIZATIONWITHASTRONGCHROMOPHOREORFLUOROUNLESSTHEREISACLEANUPPROCEDUREFORTHEIRELIMINATIONITISTHUSHIGHLYDESIRABLETODEVELOPASIMPLECORRESPONDINGAUTHORANDRAPIDMETHODTHATREQUIRESNOSUCHPROCEDURE00219673/97/1700COPYRIGHT?1997ELSEVIERSCIENCEBVALLRIGHTSRESERVEDPIIS0021967396009065TFUSEETAL/JCHROMATOGRA7641997177–1821793RESULTSANDDISCUSSIONTHATAPPLIEDPOTENTIALTHATWOULDGIVETHEREDUCTIONCURRENTOFPROTONATEDQUINONETHEREDUCTIONPOTENTIALOFPROTONATEDQUINONEWAS31VOLTAMMETRICREDUCTIONOFVKINTHEPRESENCELESSNEGATIVETHANTHATOFDISSOLVEDOXYGENTHE3OFFATTYACIDSHALFPEAKPOTENTIALOFTHEFIRSTREDUCTIONWAVEOFOXYGENINETHANOLCONTAINING38MMLICLOWAS4PROTONATIONOFQUINONEATTHEELECTRODESURFACE2730MVVSSCEHOWEVER,THEREMAYHAVEBEENOCCURSPRIORTOITSELECTRONTRANSFERPROTONATEDBACKGROUNDCURRENTDUETOTHEDISSOLVEDOXYGEN,QUINONEISREDUCEDATAPOTENTIALLESSNEGATIVETHANSINCETHEOXYGENWASREDUCEDATPOTENTIALSMORETHATOFQUINONETOGIVEANEWPEAKONTHEVOLTNEGATIVETHAN2300MVVSSCEAMMOGRAMOFQUINONE17,18HIGHERFATTYACIDS,SUCHASPALMITICACID,INANETHANOLSOLUTIONCON32HPLCECDTAININGVKANDLICLOWEREPREVIOUSLYFOUNDTO34GIVERISETOAPEAKOFPROTONATEDVKONTHEINCONSIDERATIONOFTHEABOVE,HPLCECDOFFATTY3VOLTAMMOGRAMOFVKATAPOTENTIALLESSNEGATIVEACIDSWASCARRIEDOUTREVERSEDPHASESEPARATIONOF3THANTHEREDUCTIONPOTENTIALOFVKVKITSELFGAVEHIGHERFATTYACIDSWASDONEUSINGANODSCOLUMN33ACLEARREDUCTIONPEAKAT2720MVVSSCE,ANDAANDAMPOFANETHANOL–ACETONITRILEMIXTURETHEPEAKOFPROTONATEDVKWASNOTEDAT2320MVVSDISSOLVEDOXYGENINMPANDTHEQUINONESOLUTION3SCEAFTERADDINGPALMITICACIDTOTHESOLUTIONTHEWASREMOVEDBYTHEDEGASSORA20MLALIQUOTOFPEAKHEIGHTWASPROPORTIONALTOADDEDACIDCONSOLUTIONCONTAININGFATTYACIDSWASINJECTEDINTOTHECENTRATION16COLUMNTHEELUATEWASMIXEDWITHTHEQUINONETHEHALFPEAKPOTENTIALOFAPEAKOFPROTONATEDSOLUTIONANDTHEFATTYACIDSWASDETECTEDWITHECDVKWASPREVIOUSLYSHOWNTOSHIFTTOAMOREEXAMINATIONWASMADEOFHOWTHERATIOOFACETONI3NEGATIVEPOTENTIALACCOMPANIEDBYANINCREASEINPKTRILETOETHANOLINTHEMPINFLUENCEDTHESEPARATIONAOFTHEADDEDACID17HOWEVER,HALFPEAKPOTENTIALSANDSENSITIVITYFORACIDDETERMINATIONINFIG2,THEOFPREPEAKSFORDIFFERENTHIGHERFATTYACIDSWERERETENTIONTIMEAANDTHEPEAKHEIGHTSBOFSIGNALSESSENTIALLYTHESAME,SINCEACIDSTRENGTHWASNEARLYFOR200PMOLLINOLEIC,OLEIC,PALMITICANDSTEARICACIDTHESAMEEACHFATTYACIDCOULDTHUSBEDETECTEDATWEREPLOTTEDAGAINSTTHERATIOOFTHETWOSOLVENTS,INFIG2RETENTIONTIMEAANDPEAKHEIGHTBASFUNCTIONSOFSOLVENTRATIOOFTHEMOBILEPHASEALINOLEICACID,BOLEICACID,CPALMITICACID,DSTEARICACIDAMOUNTOFACID5200PMOLHPLCCONDITIONSQUINONESOLUTION,6MMVK176MMLICLOINETHANOL–ACETONITRILE34MIXTURESAMPLEVOLUME,20MLCOLUMN,LICHROSPHER100RP18250MM34MMID,5MMCOLUMNTEMPERATURE,ROOMTEMPERATUREFLOWRATE,11ML/MINAPPLIEDPOTENTIAL,2415MVVSSCE
下載積分: 10 賞幣
上傳時間:2024-03-13
頁數(shù): 6
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簡介:HINDAWIPUBLISHINGCORPORATIONINTERNATIONALJOURNALOFAGRONOMYVOLUME2012,ARTICLEID543230,7PAGESDOI101155/2012/543230RESEARCHARTICLEIMPROVEMENTOFSOYBEANOILSOLVENTEXTRACTIONTHROUGHENZYMATICPRETREATMENTFVGRASSO,1PAMONTOYA,1CCCAMUSSO,1,2ANDBGMAROTO1,21FACULTADDECIENCIASEXACTAS,F′ISICASYNATURALES,UNIVERSIDADNACIONALDEC′ORDOBA,AVENUEVELEZSARSFIELD1200,5000C′ORDOBA,ARGENTINA2FACULTADDECIENCIASAGROPECUARIAS,UNIVERSIDADNACIONALDEC′ORDOBA,AVENUEVALPARA′ISOS/NO,5000C′ORDOBA,ARGENTINACORRESPONDENCESHOULDBEADDRESSEDTOFVGRASSO,FGRASSOAGROUNCEDUARRECEIVED5NOVEMBER2011REVISED14FEBRUARY2012ACCEPTED6MARCH2012ACADEMICEDITORBERTRANDMATTH¨AUSCOPYRIGHT?2012FVGRASSOETALTHISISANOPENACCESSARTICLEDISTRIBUTEDUNDERTHECREATIVECOMMONSATTRIBUTIONLICENSE,WHICHPERMITSUNRESTRICTEDUSE,DISTRIBUTION,ANDREPRODUCTIONINANYMEDIUM,PROVIDEDTHEORIGINALWORKISPROPERLYCITEDTHEPURPOSEOFTHISSTUDYISTOEVALUATEMULTIENZYMEHYDROLYSISASAPRETREATMENTOPTIONTOIMPROVESOYBEANOILSOLVENTEXTRACTIONANDITSEVENTUALADAPTATIONTOCONVENTIONALPROCESSESENZYMATICACTIONCAUSESTHEDEGRADATIONOFTHECELLSTRUCTURESTHATCONTAINOILIMPROVEMENTSINTERMSOFEXTRACTION,YIELD,ANDEXTRACTIONRATEAREEXPECTEDTOBEACHIEVEDSOYBEANFLAKESANDCOLLETSWEREUSEDASMATERIALSANDHEXANEWASUSEDASASOLVENTTEMPERATURE,PH,ANDINCUBATIONTIMEWEREOPTIMIZEDANDDIFFUSIONCOEFFICIENTSWEREESTIMATEDFOREACHSOLIDEXTRACTIONSWERECARRIEDOUTINACOLUMN,OILCONTENTWASDETERMINEDACCORDINGTOTIME,ANDAMATHEMATICALMODELWASDEVELOPEDTODESCRIBETHESYSTEMTHEOPTIMUMCONDITIONSOBTAINEDWEREPH54,38?C,AND97H,ANDPH58,44?C,AND58HOFTREATMENTFORFLAKESANDCOLLETS,RESPECTIVELYHYDROLYZEDSOLIDSEXHIBITEDAHIGHERYIELDDIFFUSIONCOEFFICIENTSWEREESTIMATEDBETWEEN10?11AND10?10THEHIGHESTDIFFUSIONCOEFFICIENTWASOBTAINEDFORHYDROLYZEDCOLLETS073GOIL/MLAND07GOIL/MLWEREOBTAINEDAT240SINACOLUMNFORCOLLETSANDFLAKES,RESPECTIVELYHYDROLYZEDSOLIDSEXHIBITEDAHIGHERYIELDTHEENZYMATICINCUBATIONACCELERATESTHEEXTRACTIONRATEANDALLOWSFORHIGHERYIELDTHEPROPOSEDMODELPROVEDTOBEAPPROPRIATE1INTRODUCTIONSEEDOILSREPRESENT70OFGLOBALOILPRODUCTION,OFWHICH30ISSOYBEANOILOILSEEDSARETHEMOSTIMPORTANTEXPORTITEMSINARGENTINA1INOILSEEDS,THEVACUOLESWITHINCELLSCONTAINOIL,ANDBOTHCELLWALLSANDVACUOLESHAVETOBEBROKENINORDERTOIMPROVESOLVENTEXTRACTIONTHEREFORE,THEPREPARATIONOFTHESEEDBEFORESOLVENTEXTRACTIONISCRITICALTOMAXIMIZEOILRECOVERYANALTERNATIVEPRETREATMENTTOFACILITATETHERELEASEOFOILFROMTHESEEDCOULDBEENZYMATICDEGRADATIONINTHISWAY,THEPARTIALHYDROLYSISOFSOYBEANSEEDCELLSTRUCTURESWITHAPPROPRIATEENZYMESWOULDINCREASEPERMEABILITY,WHICHWOULDINTURNINCREASEMASSTRANSFER2ANENZYMATICTREATMENTSTAGECOULDBEINCORPORATEDFORINDUSTRIALPURPOSESWITHOUTSIGNIFICANTCHANGESTOCONVENTIONALPROCESSESTHEOILRELEASEOBTAINEDUSINGTHISMETHODCOULDRESULTINAHIGHEREXTRACTIONYIELDAND/ORSMALLERQUANTITIESOFTHEORGANICSOLVENTSUSED3INSOLVENTEXTRACTION,PRETREATEDOILSEEDSPOROUSSOLIDMATRIXCOMEINTOCONTACTWITHAPURESOLVENTORASOLVENTMIXTUREMISCELLATOTRANSFERTHEOILFROMTHESOLIDMATRIXTOTHELIQUIDMEDIUMWHILETHEPRINCIPLEOFEXTRACTIONISRELATIVELYSIMPLE,ITISACOMPLEXMECHANISM4INORDERTODESCRIBETHISPROCESS,THEMASSTRANSFERPHENOMENAINVOLVEDANDTHEEVENTUALRESISTANCETOMASSTRANSFERINTHESOLIDPHASESOLIDSOYBEANANDINTHELIQUIDPHASEHEXANESHOULDBEANALYZEDTHISPROCESSINVOLVESSEVERALPHENOMENAOILISDIFFUSEDTHROUGHTHEINTERNALPORESTOTHESURFACEOFTHESOLIDINTERNALMASSTRANSPORTANDISTHENPASSEDTOTHEBULKLIQUIDBYMEANSOFACONVECTIVEMECHANISMPRODUCEDBYTHECONCENTRATIONDIFFERENCEBETWEENTHESOLUTIONOCCLUDEDINTHEPORESANDTHEBULKSOLUTIONEXTERNALTRANSPORTBECAUSETHEOILTOBEEXTRACTEDISCONTAINEDWITHINANINSOLUBLESOLIDNETWORKWITHOCCLUDEDMISCELLA,THEDIFFUSIONOCCURSMAINLYBETWEENTHEOCCLUDEDSOLUTIONANDTHESOLID,GREATLYAFFECTINGTHEEXTRACTIONRATESINCETHESOLIDMATRIXRESISTSDIFFUSIVETRANSPORT5INTERNATIONALJOURNALOFAGRONOMY3PROPOSEDBYMANYAUTHORS12–14,ANDCARR′INANDCRAPISTE4?C?TDEF?2C?X21WITHTHEFOLLOWINGINITIALANDBOUNDARYCONDITIONSFORANUNLIMITEDANDPERFECTLYAGITATEDVOLUMEOFBULKLIQUIDFORT0,CCO,FORT0,C0,INX?L,XL2THESOLUTIONTO1WASOBTAINEDFORPLATEANDSPHERE,ACCORDINGTOTHESOLIDTHATWASCONSIDEREDTHEFOLLOWINGWASOBTAINEDBYINTEGRATINGEACHSOLUTIONANDTAKINGINTOACCOUNTTHATTHESERIESOBTAINEDCONVERGERAPIDLYFORPLATEWITHTHICKNESS2L,QQ08Π2E?Π2DT/2L23FORSPHEREWITHRADIUSR,QQ06Π2E?Π2DEFT/R24BECAUSETHETRIGLYCERIDESPRESENTINVEGETABLEOILHAVEDIFFERENTMOLECULARWEIGHTSANDSTRUCTURES,ITISEASIERTOMEASURETHEAMOUNTOFOILINRELATIONTOSOLIDMASSTHEREFORE,THEC/COCONCENTRATIONRATIOWASTURNEDINTOAQ/Q0QUANTITYRATIOINBOTHEQUATIONS12EQUATIONS3AND4WERELINEARIZEDANDREPRESENTEDACCORDINGTOTIMETTHESLOPEOFBOTHLINESWASUSEDTOEVALUATETHEEFFECTIVEDIFFUSIONCOEFFICIENTSMATHEMATICALMODELFORCOLUMNEXTRACTIONTHEFIXEDBEDWASREGARDEDASASECTIONOFANEXTRACTIONCOLUMNTOWHICHASTEADYSTREAMOFHEXANE,QLO,ISSUPPLIEDANDFROMWHICHTHESAMEFLOWOFMISCELLA,QL,ISEXTRACTEDTHEMASSBALANCESFOREACHPHASEWERETHEFOLLOWINGSOLID?DCSDTKSAVS??CS?KEQCL?5LIQUIDDCLDT?QLCLVLKLAVL??CSKEQ?CL?6INTHEMASSBALANCEESTIMATION,ITWASASSUMEDTHATTHEBEDWASMADEUPOFPOROUSPARTICLESISOTROPICANDSPHERICALPARTICLESFORCOLLETSWITHANDWITHOUTENZYMATICPRETREATMENTANDFORFLAKESWITHENZYMATICTREATMENTTHEOILCONTENTINEACHOFTHESOLIDSISUNIFORMINALLPARTICLES,ANDTHEOILBEHAVESASASINGL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下載積分: 10 賞幣
上傳時間:2024-03-13
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下載積分: 10 賞幣
上傳時間:2024-03-13
頁數(shù): 4
大小: 2.3(MB)
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