封面文章

封面文章

化學(xué)

數(shù)據(jù)庫檢索號：0567-7351-201403000289

石墨烯是由sp2雜化碳原子組成的具有蜂窩狀結(jié)構(gòu)的二維原子晶體．石墨烯的共價化學(xué)修飾是石墨烯研究領(lǐng)域的一個新的熱點，也是石墨烯材料的表面改性和能帶調(diào)控、以及合成新型二維石墨烯衍生物的重要途徑．完整的二維蜂窩結(jié)構(gòu)和離域大π鍵使得石墨烯的化學(xué)性質(zhì)非常穩(wěn)定，難以通過常規(guī)的化學(xué)反應(yīng)獲得高效的表面修飾，這是石墨烯共價化學(xué)的主要挑戰(zhàn)．近年來，我們發(fā)展了一系列基于光化學(xué)原理的石墨烯共價修飾方法，利用光化學(xué)過程產(chǎn)生的活性自由基實現(xiàn)了石墨烯的高效共價加成和氧化反應(yīng)，為石墨烯的光化學(xué)能帶工程奠定了理論和實驗基礎(chǔ)．本文將以這些研究成果為主線，系統(tǒng)地闡述石墨烯的光化學(xué)修飾方法及其二維反應(yīng)特性，并對該領(lǐng)域的未來發(fā)展趨勢和所面臨的挑戰(zhàn)進(jìn)行簡要的展望．

石墨烯；光化學(xué)；自由基；光氯化；光催化；非對稱修飾

數(shù)據(jù)庫檢索號：0253-3820-201403000355

引用格式：激光剝蝕-電感耦合等離子體質(zhì)譜法原位分析印度芥菜中Cd、P、S、Cu等7種元素．分析化學(xué),2014,42(3):355-359

封面介紹：On page355,YANG etal developed an in vivo analysismethod for imaging of tracemetal distribution in the stem of Indian mustard by laser ablation-inductively coupled plasma mass spectrometry(LA-ICP-MS).The results indicated that LA-ICP-MS is useful for the study of spatial elemental distribution and has great potential for applications in other areas of plant pathology research.

激光剝蝕-電感耦合等離子體質(zhì)譜法原位分析印度芥菜中Cd、P、S、Cu等7種元素

楊紅霞，趙令浩，高津旭，劉崴，李冰

摘要：建立了莖中7種元素Cd，P，S，K，Ca，Cu和Zn的LA-ICP-MS原位分析及二維成像方法，并研究了其在鎘富集型印度芥菜莖中的分布特征．印度芥菜經(jīng)50μmol/L Cd處理14 d后，利用包埋劑包埋，冷凍切片后，用Nd：YAG laser(213 nm)器掃描，激光剝蝕-電感耦合等離子體質(zhì)譜法(ICP-MS)測定各元素強度，同時選擇13C作為內(nèi)標(biāo)元素，對各元素強度進(jìn)行標(biāo)準(zhǔn)化處理．結(jié)果表明，在富集型印度芥菜莖部，Cd大量積聚于由韌皮部與木質(zhì)部組成的維管組織中，除此以外，莖的韌皮部細(xì)胞中及表皮層也分布著大量的Cd．7種元素的分布相關(guān)性表明，Cd與Ca具有相似的分布規(guī)律，而K和Ca，P和S的分布呈顯著正相關(guān)．說明重金屬元素進(jìn)入植株體內(nèi)并被其吸收運輸過程是伴隨著植物對其它元素的吸收，且具有相似的運輸機制．本研究建立的元素原位分析方法證明LA-ICP-MS在植物樣品中元素空間分布的研究方面具有很大的潛力．

關(guān)鍵詞：激光剝蝕-電感耦合等離子體質(zhì)譜法；印度芥菜；原位分析；鎘；磷

數(shù)據(jù)庫檢索號：1000-6818-201403000535

引用格式：納米薄層HZSM-5分子篩催化甲醇制丙烯．物理化學(xué)學(xué)報,2014,30(3):535-543

封面介紹：The cover image presentsmethanol to propylene(MTP)over nanosheets of HZSM-5 zeolite w ith w ide(010)surface.On page 535,ZHANG et al.demonstrate that the nanosheets of HZSM-5 zeolite show higher propylene selectivity,total three olefins’selectivity(ethylene,propylene, and C4alkenes),and longer catalytic lifetime than the nanosized HZSM-5 zeolite.The good MTP catalytic performance of the nanosheets of HZSM-5 zeolite can be attributed to their w ide(010) surface,high externalsurface area,and largemesopore volume.

納米薄層HZSM-5分子篩催化甲醇制丙烯

張少龍，張?zhí)m蘭，王務(wù)剛，閔媛媛，馬通，宋宇，鞏雁軍，竇濤

摘要：在合成系列硅鋁比納米薄層HZSM-5分子篩的基礎(chǔ)上，研究了納米薄層HZSM-5分子篩催化甲醇制丙烯(MTP)的反應(yīng)性能．在固定床微反裝置上詳細(xì)考察了工藝條件對納米薄層HZSM-5分子篩催化性能的影響，同時與納米HZSM-5分子篩對MTP反應(yīng)的催化性能進(jìn)行了比較．結(jié)果表明，納米薄層HZSM-5分子篩具有較高的目的產(chǎn)物選擇性和較長的催化壽命．在適宜硅鋁比(n(SiO2)/n(A l2O3)=213)和反應(yīng)條件下(溫度470℃，甲醇質(zhì)量空速為3 h-1)，丙烯的選擇性達(dá)到46.7%，三烯(乙烯、丙烯和C4烯烴)選擇性達(dá)到78.7%．其中，丙烯/乙烯的質(zhì)量比可達(dá)到6.5，是納米HZSM-5分子篩的2倍，而芳烴的選擇性比納米分子篩明顯降低．這是因為納米薄層HZSM-5分子篩比納米HZSM-5分子篩具有較寬的(010)晶面、較大的外比表面積和介孔孔容．

關(guān)鍵詞：納米薄層；HZSM-5分子篩；甲醇；丙烯

數(shù)據(jù)庫檢索號：0253-9837-201403000286

引用格式：Ni-Mo氮化物催化劑：合成及其丙烷氨氧化催化性能．催化學(xué)報,2014,35(3):286-293

封面介紹：范曉強等發(fā)現(xiàn)鎳鉬氧化物前驅(qū)體的制備方法影響其氮化物催化劑的物理化學(xué)性質(zhì)，進(jìn)而影響其丙烷氨氧化性能，氮化物中的活性氮物種對丙烷氨氧化反應(yīng)中丙烯腈的選擇性起重要作用．見本期第286-293頁．

Ni-Mo氮化物催化劑：合成及其丙烷氨氧化催化性能

范曉強，張惠民，李建梅，趙震，徐春明，劉堅，段愛軍，姜桂元，韋岳長

摘要：分別采用溶膠-凝膠法、旋轉(zhuǎn)蒸發(fā)微波干燥法、共沉淀法、浸漬法和機械混合法制備Ni-Mo氧化物前驅(qū)體．以H2和N2的混合氣為氮化氣體，采用程序升溫氮化法合成了鎳鉬氮化物催化劑．利用X射線衍射、總氮含量分析、X射線光電子能譜及H2程序升溫還原對Ni-Mo氧化物前體及氮化物催化劑進(jìn)行了表征．將上述Ni-Mo氮化物催化劑用于丙烷氨氧化反應(yīng)中．結(jié)果表明，Ni-Mo氧化物前驅(qū)體的制備方法影響其氮化物催化劑上丙烷氨氧化反應(yīng)性能．Ni-Mo氮化物催化劑中氮物種的移動性及反應(yīng)性對產(chǎn)物丙烯腈選擇性的影響較大，共沉淀法制備的催化劑存在大量的活性氮物種，因而具有良好的催化丙烷氨氧化反應(yīng)活性．

關(guān)鍵詞：鎳鉬氮化物；丙烷氨氧化；丙烯腈；制備方法；氮物種

地質(zhì)學(xué)

數(shù)據(jù)庫檢索號：0023-074X-201408000679

引用格式：周口店第1地點用火的磁化率和色度證據(jù)．科學(xué)通報,2014,59(8):679-686

封面介紹：古人類的控制用火問題是人類演化研究中的重要課題．周口店北京猿人遺址在早期人類用火研究方面有著極其重要的地位，在二十世紀(jì)二三十年代遺址發(fā)掘過程中，就陸續(xù)發(fā)現(xiàn)了燒骨、灰燼等一系列用火遺跡，成為當(dāng)時最早的人類控制用火證據(jù)．然而近年來一些學(xué)者對這些證據(jù)提出了質(zhì)疑，認(rèn)為它們的來源具有不確定性，不能作為人類用火的證據(jù)，在學(xué)界引起了廣泛爭議．對北京猿人遺址最新一次發(fā)掘過程中新發(fā)現(xiàn)的疑似人類用火堆積進(jìn)行詳細(xì)的巖石磁學(xué)和色度分析發(fā)現(xiàn)，這些沉積物具有非常高的磁化率和紅度值，很可能經(jīng)歷過700℃以上的高溫加熱．這些結(jié)果很可能指示著北京猿人長期、反復(fù)用火的過程，而不是自然火或者自然界地質(zhì)過程的產(chǎn)物．詳見張巖等人文(p679)．

周口店第1地點用火的磁化率和色度證據(jù)

張巖，郭正堂，鄧成龍，張雙權(quán)，吳海斌，張春霞，葛俊逸，趙得愛，李琴，宋揚，朱日祥

摘要：針對周口店北京猿人遺址是否存在原地用火證據(jù)的爭議，對遺址第1地點第4堆積層(據(jù)賈蘭坡1959劃分方案)中新發(fā)現(xiàn)的疑似用火遺跡進(jìn)行系統(tǒng)野外采樣以及磁化率和色度測量．結(jié)果顯示，部分疑似用火區(qū)沉積物的磁化率、紅度均顯著異常，磁化率值較周圍沉積物高出22倍，紅度高出近3倍．高磁化率值和高紅度值分別由高溫作用過程中新生成的細(xì)粒磁鐵礦和赤鐵礦顆粒引起．漫反射光譜分析表明，疑似用火區(qū)沉積物的赤鐵礦-針鐵礦組成與平面其他部位及第2，3地點自然樣品顯著不同．磁化率隨溫度變化特征進(jìn)一步揭示出疑似用火區(qū)沉積物很可能經(jīng)歷了700℃以上的加熱，而自然火一般無法達(dá)到如此高的溫度．這些磁性、色度異常的沉積物很可能受到人類控制用火的作用，但其為原地用火區(qū)堆積還是曾經(jīng)歷再搬運，還需要進(jìn)一步研究．

關(guān)鍵詞：周口店；控制用火；磁化率；色度；巖石磁學(xué)

古生物學(xué)

數(shù)據(jù)庫檢索號：0023-074X-201409000796

引用格式：早期海綿的四輻射對稱性．科學(xué)通報,2014,59(9):796-802

封面介紹：目前學(xué)術(shù)界對最古老后生動物門類的分支序列及系統(tǒng)演化仍未達(dá)成共識，但大多數(shù)學(xué)者都認(rèn)為海綿動物是最早分支的后生動物．海綿有看似原始的細(xì)胞結(jié)構(gòu)特征和簡單的骨架建構(gòu)，前人從分子系統(tǒng)演化研究也證實了它們的原始性．現(xiàn)生海綿部分屬種有似輻射對稱、少部分有順軸旋系對稱，因此，前人的研究均認(rèn)為海綿是沒有軸性對稱的．中國科學(xué)院南京地質(zhì)古生物研究所早期生命研究組從全球已知最古老的海綿動物群中識別出四輻射對稱性，并且從已報道的柱狀海綿化石中鑒別出前人所忽略的四輻射對稱結(jié)構(gòu)，指出四輻射對稱是海綿的原始特征，由此推測最早的海綿始祖應(yīng)該是由基因控制、外形規(guī)整、細(xì)胞結(jié)構(gòu)交織而成的海綿體．封面展示了具有四輻射對稱性的化石海綿復(fù)原圖．詳見BOTTING Joseph P.等人文(p796).

早期海綿的四輻射對稱性

BOTTING Joseph P.，袁訓(xùn)來，林日白

摘要：目前學(xué)術(shù)界對最古老后生動物門類的分支序列及系統(tǒng)演化仍沒有共識，但大多數(shù)學(xué)者都深信海綿動物是最早分支的后生動物．現(xiàn)生海綿部分屬種有似輻射對稱、少部分有順軸旋系對稱，因此，海綿被認(rèn)為是在真后生動物發(fā)育特征，如有明確的軸性對稱出現(xiàn)之前演化的動物．其他早期后生動物門類有兩側(cè)對稱、四輻射對稱(刺胞動物門)、二輻射對稱(櫛水母門)或是沒有對稱軸性(扁盤動物門)．本研究報道了來自華南寒武系荷塘組具有四輻對稱結(jié)構(gòu)的海綿化石，并且從已報道的柱狀海綿化石中鑒別出前人所忽略的四輻射對稱結(jié)構(gòu)．本研究指出四輻射對稱是海綿的原始特征，并且推測最早的海綿始祖應(yīng)該是由基因控制、外形規(guī)整、細(xì)胞結(jié)構(gòu)交織而成的個體．

關(guān)鍵詞：多孔動物門；安徽；荷塘生物群；骨架建構(gòu)骨針

植物學(xué)

數(shù)據(jù)庫檢索號：1672-9072-201402000181

引用格式：Farinose flavonoidsare associated w ith high freezing tolerance in fairy prim rose(Primula malacoides)plants.Journalof Integrative PlantBiology,2014,54(2):181-188

昆蟲學(xué)

微生物學(xué)

數(shù)據(jù)庫檢索號：0001-6209-201403000299

引用格式：巴氏醋酸桿菌對發(fā)酵中醋酸脅迫的生理應(yīng)答．微生物學(xué)報,2014,54(3):299-308

封面介紹：巴氏醋酸桿菌對發(fā)酵中醋酸脅迫的生理應(yīng)答(第299-308頁，江南大學(xué)工業(yè)生物技術(shù)教育部重點實驗室，中國礦業(yè)大學(xué)，徐州恒順萬通食品釀造公司，亓正良、楊海麟、夏小樂、王武、冷云偉、余曉斌、權(quán)武等人的文章)．

巴氏醋酸桿菌對發(fā)酵中醋酸脅迫的生理應(yīng)答

亓正良，楊海麟，夏小樂，王武，冷云偉，余曉斌，權(quán)武

摘要：【目的】研究Acetobacter pasteurianus CICIM B7003對醋酸發(fā)酵形成的酸脅迫環(huán)境在細(xì)胞形態(tài)、生理、代謝方面的響應(yīng)，初步提出巴氏醋桿菌的動態(tài)耐酸機制模型，為高酸度高強度液態(tài)深層醋酸發(fā)酵提供理論幫助．【方法】在9L自吸式發(fā)酵罐中用A．pasteurianus CICIM B7003發(fā)酵醋酸，選取不同生長階段細(xì)胞檢測其莢膜多糖含量、膜不飽和脂肪酸含量、耐酸基因轉(zhuǎn)錄水平、乙醇呼吸鏈酶和ATP酶活性，研究醋酸菌形態(tài)、生理和代謝隨醋酸積累的變化．【結(jié)果】醋酸的存在能減少細(xì)胞分泌莢膜多糖，發(fā)酵中多糖占細(xì)胞干重百分比由最初2.5%下降到0.89%；隨發(fā)酵進(jìn)行細(xì)胞膜不飽和脂肪酸占膜總脂肪酸含量顯著提高，致使細(xì)胞膜流動性增加；耐酸基因相對轉(zhuǎn)錄水平顯著提高而提升了細(xì)胞對酸性環(huán)境的抗性；乙醇呼吸鏈酶和ATP酶活性隨醋酸積累也顯著提高，為細(xì)胞提供足夠的能量以滿足耐酸機制對能量的需求．【結(jié)論】初步確定A．pasteurianus CICIM B7003主要依靠改變細(xì)胞膜脂肪酸組分、激活耐酸基因轉(zhuǎn)錄、增強乙醇呼吸鏈活力及快速產(chǎn)能等機制的協(xié)同作用，實現(xiàn)對酸脅迫的制衡．

關(guān)鍵詞：巴氏醋酸桿菌；醋酸發(fā)酵；醋酸脅迫；耐酸生理應(yīng)答

腫瘤學(xué)

數(shù)據(jù)庫檢索號：1000-467X-201404000176

引用格式：A bird’s eye view of the air pollution-cancer link in China.Chinese Journal ofCancer, 2014,33(4):176-188

封面介紹：Epidem iologic studieshave shown that theaging of the population isamajor factor for the increased incidence of cancer.W ith the remarkable industrialization and urbanization in China in the past 30 years,air pollution has become a ubiquitous problem in China,especially in northern and eastern China.During the w inter months of late 2013 and early 2014,northern China has been frequently filled w ith fog-like haze that blurs visibility.Many of the pollutants have reached a level more than 10 times higher than the lower unhealthy lim it(Air Quality Index of 50)recommended by WHO.This is evenmore alarm ing becauseWHO recently announced that air pollution is amutagen that causes cancer.(The art is provided by Ms.Xuan Wang,a graduate student of Tianjin University majoring in architecture design.)

Theroleofmaintenanceproteinsinthepreservationofepithelialcellidentity duringmammaryglandremodelingandbreastcancerinitiation

Yu-BeiHuang,Feng-JuSong,QunLiu,Wei-QinLi,WeiZhang,Ke-XinChen

Abstract:Air pollution in China comes from multiple sources,including coal consumption,construction and industrial dust,and vehicle exhaust.Coal consumption in particular directly determines the emissions of threemajor air pollutants：dust,sulfur dioxide(SO2),and nitrogen oxide(NOx).The rapidly increasing number of civilian vehicles is expected to bring NOxem ission to a very high level.Contrary to expectations, however,existing data show that the concentrations ofmajor pollutants[particulatematter-10(PM10),SO2,and nitrogen dioxide(NO2)]in several large Chinese cities have declined during the past decades,though they still exceed the national standards of ambient air quality.Archived data from China does not fully support that the concentrations of pollutants directly depend on local emissions,but this is likely due to inaccurate measurement of pollutants.Analyses on the cancer registry data show that cancer burden related to air pollution is on the rise in China and w ill likely increase further,but there isa lack of data to accurately predict the cancerburden.Pastexperience from other countrieshassounded alarm of the link between air pollution and cancer.The quantitative association requires dedicated research aswell as establishmentof neededmonitoring infrastructuresand cancer registries.The air pollution-cancer link isa seriouspublic health issue thatneedsurgentinvestigation.

Keywords:Lung cancer;airpollution;particulatematter;sulfur dioxide;nitrogen oxide

藥學(xué)

數(shù)據(jù)庫檢索號：1000-7857-201411000021

引用格式：茶多酚EGCG對小鼠棕色脂肪代謝的影響．科技導(dǎo)報,2014,32(11):21-25

封面介紹：《科技導(dǎo)報》2014年11期第21-25頁刊登了商悅等的文章“茶多酚EGCG對棕色脂肪代謝的影響”．該文采用動物實驗、病理組織學(xué)方法、免疫組化法，表明不同種屬小鼠的棕色脂肪組織具有不同的組織形態(tài)學(xué)特點，EGCG能夠在一定程度上降低小鼠的體重和白色脂肪的含量，能夠通過增加棕色脂肪細(xì)胞內(nèi)UCP1的表達(dá)來調(diào)節(jié)棕色脂肪的代謝，從而調(diào)節(jié)小鼠的脂質(zhì)代謝．這篇文章為研究茶葉或茶多酚的脂質(zhì)代謝調(diào)節(jié)機制提供了實驗依據(jù)．本期封面圖片為實驗用昆明小鼠，由陳淑珍提供．

茶多酚EGCG對小鼠棕色脂肪代謝的影響

商悅，李毅，陳淑珍，甄永蘇

摘要：隨著對棕色脂肪組織(BAT)在成人體內(nèi)具有生物學(xué)功能的肯定，棕色脂肪已經(jīng)成為當(dāng)今醫(yī)學(xué)研究的熱點．采用動物實驗、病理組織學(xué)方法及免疫組化，觀察了表沒食子兒茶素沒食子酸酯(EGCG)對棕色脂肪代謝的影響．結(jié)果表明，在體重和鼠齡相近時，不同種屬小鼠肩甲間棕色脂肪組織HE染色后的形態(tài)不同，C57BL/6脂肪細(xì)胞中的空泡大，胞漿含量少，BALB/c小鼠脂肪細(xì)胞中的空泡小，胞漿含量多，昆明小鼠居中．給昆明小鼠口服不同劑量EGCG后，150mg/kg EGCG能降低小鼠體重的增長，降低附睪周圍白色脂肪組織的重量，但沒有統(tǒng)計學(xué)意義．同時，EGCG能降低棕色脂肪細(xì)胞內(nèi)脂肪含量，增加胞漿含量，具有統(tǒng)計學(xué)意義(P＜0.001)．免疫組化結(jié)果表明，EGCG能增加棕色脂肪細(xì)胞內(nèi)脫偶聯(lián)蛋白1(UCP1)的表達(dá)，增加能量代謝．因此，不同種屬小鼠的BAT具有不同的組織形態(tài)學(xué)特點，這為研究BAT小鼠的選擇提供了依據(jù)；EGCG能夠調(diào)節(jié)小鼠棕色脂肪的代謝功能，這為進(jìn)一步研究作用機制打下了基礎(chǔ)，同時為茶葉在脂肪代謝方面的調(diào)節(jié)提供了一種新的思路和依據(jù)．

關(guān)鍵詞：表沒食子兒茶素沒食子酸酯；棕色脂肪組織；脫偶聯(lián)蛋白1

化學(xué)工業(yè)

數(shù)據(jù)庫檢索號：0438-1157-201403000805

引用格式：微反應(yīng)器內(nèi)入口結(jié)構(gòu)對Taylor氣泡形成過程的影響．化工學(xué)報,2014,65(3):805-812封面介紹：Taylor流因具有軸向返混低、徑向混合強等特性，在眾多領(lǐng)域有廣闊應(yīng)用前景。封面圖片給出了以空氣-水為氣-液兩相體系，表觀氣速與表觀液速分別為0.361m·s-1和0.221m·s-1時，Taylor氣泡形成過程的可視化實驗結(jié)果(左圖)與數(shù)值模擬結(jié)果(右圖)的比較。由圖可見，數(shù)值模擬與實驗觀察的氣泡長度、形狀及形成周期都基本一致。說明該數(shù)值模擬方法能很好地模擬微通道內(nèi)氣-液兩相Taylor流。詳見本期805-812頁。

微反應(yīng)器內(nèi)入口結(jié)構(gòu)對Taylor氣泡形成過程的影響

黨敏輝,任明月,陳光文

摘要：采用計算流體力學(xué)方法，考察了微通道入口結(jié)構(gòu)、氣液比及兩相混合速度對Taylor氣泡形成過程的影響，模擬結(jié)果與可視化實驗符合良好。與單純流體體積法相比，水平集法(level set)和流體體積法(volume of fluid)相耦合的方法(coupled level set and volume of fluid method，CLSVOF)可獲得更精確的氣液界面，且CLSVOF法結(jié)果與實驗結(jié)果更符合。數(shù)值模擬結(jié)果發(fā)現(xiàn)，通道入口結(jié)構(gòu)及氣液比對氣泡長度、氣泡生成頻率及氣泡體積有很大影響。氣液比恒定，不同通道入口結(jié)構(gòu)，兩相混合速度對氣泡長度有不同影響。

關(guān)鍵詞：泰勒流；兩相流；計算流體力學(xué)；微通道；微反應(yīng)器；入口結(jié)構(gòu)

數(shù)據(jù)庫檢索號：1004-9541-201405000509

引用格式：Effects of Oxygen Transfer Limitation and Kinetic Control onBiomimetic Catalytic Oxidation of Toluene．Chinese JournalofChemical Engineering,2014,22(5):509-515

封面介紹：Effects of both oxygen transfer and kinetic control onoxidation of toluene over metalloporphyrinsweresystematicallyinvestigated．The results showed that the conversion under the oxygen transfer lim itations was lower than that under kinetic control．And the total selectivity to benzaldehyde and benzylalcoholunder the oxygen transfer lim itationswould decrease in comparison w ith that under kinetic control in the same conversion．Under the kinetics control,oxygen transferwouldn’t influence conversion and the selectivity of benzaldehydeand benzylalcohol,and toluene oxidation is zero-order w ith respect to oxygen.And some possible explanations have been discussed(see LUO etal．Pages509-515)．

EffectsofOxygenTransferLimitationandKineticControlonBiomimetic CatalyticOxidationofToluene

LUOWeiping(羅偉平),LIUDawei(劉大為),SUNJun(孫俊),DENGWei(鄧偉),SHENG Wenbing(盛文兵),LIUQiang(劉強),GUOCancheng(郭燦城)

Abstract:Under oxygen transfer lim itation and kinetic control,liquid-phase catalytic oxidation of toluene overmetalloporphyrin was studied. An improved technique ofmeasuring dissolved oxygen levels for gas-liquid reaction at the elevated temperature and pressurewasused to take the sequential data in the oxidation of toluene catalyzed by metalloporphyrin.By this technique the corresponding control step of toluene oxidation could be obtained by varying reaction conditions.When the partial pressure of oxygen in the feed is lower than or equal to 0.070MPa at463K,the oxidation of toluene would be controlled by oxygen transfer,otherw ise the reaction would be controlled by kinetics.The effects of both oxygen transfer and kinetic control onthe toluene conversion and the selectivity of benzaldehyde and benzylalcohol in biomimetic catalytic oxidation of toluene were systematicallyinvestigated.Three conclusions have been made from the experimental results.Firstly,under the oxygen transfer lim itation the toluene conversion is lower than that under kinetic control at the same oxidation conditions.Secondly,under the oxygen transfer lim itation the total selectivity of benzaldehyde and benzylalcohol is lower than that under kinetic control w ith the same conversion of toluene. Finally,under the kinetics control the oxidation rate of toluene is zero-orderw ith respect to oxygen.The experimental results are identicalw ith the biomimetic catalyticmechanism of tolueneoxidation overmetalloporphyrins.

Keywords:kinetic control;oxygen transfer lim itations;catalysis;toluene;oxidation;porphyrin

封面介紹：Farinose Flavone in Frost Protection During cold seasons,fairy prim roses secrete various amounts of farinose flavone through specialized trichomes.In this issue,Isshiki et al.(pp.181-188) query the role of flavone in frost protection,and observed that the ice nucleation temperatures closely correlated w ith amounts of flavone produced by selected cultivars,and exogenous application of flavone efficiently protected leavesand buds from freezing.

Farinoseflavonoidsareassociatedwithhighfreezingtoleranceinfairy primrose(Primulamalacoides)plants

RyutaroIsshiki,IvanGalis,ShigemiTanakamaru

The deposition of surface(farinose)flavonoidson aerial partsof some Primula species isawell-documented butpoorly understood phenomenon.Here,we show that flavonoid deposition on the leavesand winter budsmay contribute strongly to preventing freezing damage in these plants.The ice nucleation temperature of fairy prim rose(Primulamalacoides)leaves covered with natural flavonewasapproximately 6?°C lower compared to those that had their flavone artificially removed.Additionally,farinose flavonoids on the leaves reduced subsequent electrolyte leakage(EL)from the cells exposed to freezing temperatures.Interestingly,exogenous application of flavone at 4mg/g fresh weight to P.malacoides leaves,which had the original flavonemechanically removed,restored freezing tolerance,and dim inished EL from the cells to pretreatment values.Our results suggest that farinose flavonoidsmay function asmediators of freezing tolerance in P.malacoides,and exogenous application of flavone could be used to reduce freezing damage during sudden butpredictable frostevents in otherplantspecies.

數(shù)據(jù)庫檢索號：1744-7917-201402000227

引用格式：Tier-1 assays for assessing the toxicity of insecticidal proteins produced by genetically engineered plants to non-targetarthropods.InsectScience,2014,21(2):227-233

封面介紹：Praying mantises such as these Pseudomantis albofimbriata show strong sexual size dimorphism(SSD).Allen et al.(2014)provides evidence that SSD can result from two different patterns of grow th and development in closely related species.See pages 227-233.Photo taken by Kate Barry.

Tier-1assaysforassessingthetoxicityofinsecticidalproteinsproducedby geneticallyengineeredplantstonon-targetarthropods

Yun-HeLi,J?rgRomeis,Kong-MingWu,Yu-FaPeng

Abstract:In assessing an insect-resistant genetically engineered(IRGE)crop before its commercialization,researchers normally use so-called“Tier-1 assays”as the initial step to determine the effects of the crop on non-targetorganisms.In these tests,the insecticidal proteins(IPs)produced by the IRGEs are added to the diets of test organisms in the laboratory.Test organisms in such assays can be directly exposed to much higher concentrationsof the test IPs than they would encounter in the field.The resultsof Tier-1 assaysare thusmore conservative than those generated in studies in which the organisms are exposed to the IPs by feeding on IRGE plant tissue or in the case of predators or parasites,by feeding on invertebrate prey or hosts thathave fed on IRGE plant tissue.In this report,we consider three important factors thatmust be considered in Tier-1 assays:(i)methods for delivery of the IP to the test organisms;(ii)the need for and selection of compounds used as positive controls;and(iii) methods formonitoring the concentration,stability and bioactivity of the IP during the assay.We also analyze the existing data from Tier-1 assays regarding the toxicity of Bt Cry proteins to non-targetarthropod species.The data indicate that thew idely used Bt proteinshaveno direct toxicity to non-targetorganisms.

artificialdiet;Cry protein;environmental risk assessment;ELISA;positive control;sensitive insectbioassay

石墨烯的光化學(xué)修飾方法．化學(xué)學(xué)報,2014,72(3):289-300

封面介紹：Based on photo-induced free radicals,various photochem ical reactionsof graphene have been developed.Using photochemical reaction of graphene as a probe,we have investigated the dimension effects on graphene chemistry,including the thickness,stacking order,single-and doubleside,and edge dependent reactivity in graphene.In this review,we select several typical examples to demonstrate such kinds of photochemical graphene engineering and its intrinsic 2D reaction characteristics.

石墨烯的光化學(xué)修飾方法

周琳，張黎明，廖磊，楊明媚，謝芹，彭海琳，劉志榮，劉忠范