APP下载

封面文章

2015-10-28

中国学术期刊文摘 2015年3期
关键词:可见

封面文章

系统科学

封面介绍:可拓学是1983年由广东工业大学研究员蔡文创立的一门横断学科.为扶持可拓学的成长,2014年8月17—18日,中国人工智能学会可拓学专业委员会、科技导报社主办的全国第14届可拓学年会在南昌召开,80余位学者与会研讨,50余篇论文参加交流.经遴选、评审、修改,《科技导报》2014年第36期出版“可拓学专题”,在“专题论文”栏目刊登7篇可拓学研究论文和综述文章,在“卷首语”等栏目发表4篇可拓学相关文章.本期封面图片源自第21-25页刊登的李珊珊等的专题论文“基于可拓基元理论的复杂社会网络分析模型”,示意了复杂社会网络的可拓基元分析方法.

基于可拓基元理论的复杂社会网络分析模型

李珊珊,刘巍,高红

针对传统社会网络分析模型存在的不足,根据可拓学中的基元理论,结合社会网络分析理念及方法,研究一种新的复杂社会网络分析模型.利用多维物元表示复杂社会网络的整体特征、节点属性和网络分析测度,丰富节点的现实涵义;利用多维关系元表示节点之间的关系,充分体现网络中关系的多重性;利用多维事元表示网络结构及环境变化的细节信息,构建了复杂社会网络的多维可拓基元分析模型.通过实例分析,验证了该模型的实用性及优越性.

复杂社会网络;分析模型;可拓基元

来源出版物:科技导报, 2014, 32(36): 21-25联系邮箱:刘巍,liuwei09@aliyun.com

地理学

来源出版物:SCIENCE CHINA Earth Sciences, 2014, 57(11): 2567-2586联系邮箱:GAO Shu, shugao@nju.edu.cn

化学

封面介绍:Porous polymer beads, containing hierarchical bimodal pore structure with gigapores and meso-macropores, relatively high surface area and uniform size, were prepared by polymerization-induced phase separation and emulsion-template technique in a glass capillary microfluidic device.

Hierarchical Porous Polymer Beads Prepared by Polymerization-induced Phase Separation and Emulsion-template in a Microfluidic Device

Wei-cai Wang, Yan-xiong Pan, Kai Shi, et al.

Abstract: Porous polymer beads(PPBs)containing hierarchical bimodal pore structure with gigapores and meso-macropores were prepared by polymerization-induced phase separation(PIPS)and emulsion-template technique in a glass capillary microfluidic device(GCMD). Fabrication procedure involved the preparation of water-in-oil emulsion by emulsifying aqueous solution into the monomer solution that contains porogen. The emulsion was added into the GCMD to fabricate the(water-in-oil)-in-water double emulsion droplets. The flow rate of the carrier continuous phase strongly influenced the formation mechanism and size of droplets. Formation mechanism transformed from dripping to jetting and size of droplets decreased from 550 μm to 250 μm with the increase in flow rate of the carrier continuous phase. The prepared droplets were initiated for polymerization by on-line UV-irradiation to form PPBs. The meso-macropores in these beads were generated by PIPS because of the presence of porogen and gigapores obtained from the emulsion-template. The pore morphology and pore size distribution of the PPBs were investigated extensively by scanning electron microscopy and mercury intrusion porosimetry(MIP). New pore morphology was formed at the edge of the beads different from traditional theory because of different osmolarities between the water phase of the emulsion and the carrier continuous phase. The morphology and proportion of bimodal pore structure can be tuned by changing the kind and amount of porogen.

Keywords: Porous polymer beads; Hierarchical; Polymerization-induced phase separation; Emulsion-template; Microfluidic device

来源出版物:Chinese Journal of Polymer Science, 2014, 32(12): 1646-1654联系邮箱:Xiang-ling Ji, xlji@ciac.ac.cn

封面介绍:自驱动光探测是指探测器利用本身的光生伏特效应实现无外加电源驱动的光探测.采用金属辅助化学刻蚀的方法制备了大面积高度有序的一维硅纳米线阵列,在其表面热蒸镀图案化金膜后制成Au/SiNWs肖特基结光探测器.研究证实在无外加偏压下,该器件可以高效、稳定、快速地响应可见-近红外光.器件有望应用于低功耗的纳米光电集成系统中.见本期论文(洪清水等.基于金/硅纳米线阵列肖特基结的自驱动式的可见-近红外光探测器性能研究),P532~P541.

基于金/硅纳米线阵列肖特基结的自驱动式的可见-近红外光探测器性能研究

洪清水,曹阳,孙家林,等

摘要:本文成功构筑了金/硅纳米线(Au/SiNWs)阵列自驱动式可见-近红外光探测器.探测器在暗态时表现出良好的二极管整流特性,在±1 V偏压下,整流比达584.在可见-近红外光照下,光探测器具有明显的光生伏特效应.光探测性能研究表明:当无外加偏压时,探测器对波长为405 nm、532 nm和1064 nm的光源具有较高的响应率,并且响应快速、信号稳定,重现性良好;当给器件施加一个很小的正偏压时,通过暗态和照光的切换,探测器可使外电路中的电流快速地正负交替变化,从而实现一种快速、有效的二进制光响应.自驱动式Au/SiNWs阵列光探测器显示了高灵敏、快速、宽光谱响应特性,具有巨大的应用前景.

关键词:自驱动;可见-近红外光探测;肖特基结;硅纳米线阵列

来源出版物:影像科学与光化学, 2014, 32(6): 532-541联系邮箱:贺军辉,jhhe@mail.ipc.ac.cn

LiNbO3不同晶面的光催化产氢性能

苏峰,徐军,夏长荣

摘要:Ba2Co9O14(BCO)是一种新型的电子-氧离子混合导体,在氧离子导体的固体氧化物燃料电池(SOFC)中,其作为阴极材料的应用可能性已经得到证实,本工作探索BCO在质子导体SOFC中的应用可能性.采用固相反应法制备BCO粉体,研究BCO与质子导体电解质BZCY(BaZr0.1Ce0.7Y0.2O3-δ)之间的化学相容性,分析BCO-BZCY复合阴极在BZCY电解质上的电化学性能.当复合阴极中BCO的质量含量为70%时,阴极性能最佳,界面阻抗活化能为1.26 eV.以BCO-BZCY为阴极,Ni-BZCY为阳极,BZCY为电解质的阳极支撑型单电池,700 ℃时,单电池的极化阻抗为0.15 Ω·cm2,最大功率密度为400 mW·cm-2.

关键词:固体氧化物燃料电池;复合阴极;质子导体电解质;Ba2Co9O14

来源出版物:无机化学学报, 2014, 30(12): 2713-2718

联系邮箱:夏长荣,xiacr@ustc.edu.cn

封面介绍:A novel method for constructing molecular pocket with high luminescence has been developed to remarkably improve the emission efficiency of inorganic/organic hybrid nanomaterials. [Liu, Huibiao et al. on page 1218-1222.]

荧光无机/有机杂化纳米分子口袋的构建

杨慧,刘礼兵,张洲,等

摘要:利用能量匹配原则将无机半导体ZnO纳米粒子与有机半导体四苯基卟啉四羧酸(TCPP)分子进行组装,在无机-有机组分之间的界面构建了杂化纳米分子口袋ZNPs-TCPP,该纳米分子口袋对四苯基卟啉(TPP)分子具有高选择性识别功能,同时其荧光增强了5倍以上,并成功地将该杂化纳米分子口袋用于肺腺癌细胞(A549)的细胞成像.

关键词:纳米分子口袋;卟啉;无机/有机杂化;细胞成像;

来源出版物:化学学报, 2014, 72(12): 1218-1222

联系邮箱:刘辉彪,liuhb@iccas.ac.cn

封面介绍:曲振平等通过添加柠檬酸钠改变羟基磷灰石(HAP)结构.柠檬酸钠改性的 HAP材料具有较高的比表面积和孔体积, 且表面分布有丰富的羟基, 这使得 HAP 材料和甲醛污染物分子之间的相互作用增强,进而提高了其甲醛催化反应活性.见本期第 1927-1936 页.

不同有机分子改性羟基磷灰石用于甲醛催化氧化

孙亚会,曲振平,陈丹,等

摘要:分别采用十六烷基三甲基溴化铵(CTAB)、十二烷基硫酸钠(SDS)及柠檬酸钠(SC)对羟基磷灰石(HAP)进行了有机改性.柠檬酸钠改性的羟基磷灰石对甲醛催化氧化表现出最好的催化活性,在240 °C实现了甲醛完全转化.通过X射线衍射、红外光谱、N2吸附-脱附、扫描电镜和热重/差重等手段对HAP结构进行了表征.结果表明,SC改性使得HAP比表面积和孔体积增加,孔径减小,更有利于吸附及传质,从而提高了其活性.此外,SC改性的HAP中羟基含量更多,更有利于甲醛与羟基之间发生相互作用,这是该样品活性提高的另一个原因.

关键词:羟基磷灰石改性;柠檬酸钠;比表面积;羟基;甲醛催化氧化

来源出版物:催化学报, 2014, 35(12): 1927-1936联系邮箱:曲振平,quzhenping@dlut.edu.cn

海洋学

An evaluation of the simulations of the Arctic Intermediate Water in climate models and reanalyses

LI Xiang, SU Jie1, ZHAO Jinping

Abstract: The simulations of the Arctic Intermediate Water in four datasets of climate models and reanalyses, CCSM3, CCSM4, SODA and GLORYS, are analyzed and evaluated. The climatological core temperatures and depths in both CCSM models exhibit deviations over 0.5and ℃200 m from the PHC. SODA reanalysis reproduces relatively reasonable spatial patterns of core temperature and depth, while GLORYS, another reanalysis, shows a remarkable cooling and deepening drift compared with the result at the beginning of the dataset especially in the Eurasian Basin(about 2℃). The heat contents at the depth of intermediate water in the CCSM models are overestimated with large positive errors nearly twice of that in the PHC. To the contrary, the GLORYS in 2009 show a negative error with a similar magnitude, which means the characteristic of the water mass is totally lost. The circulations in the two reanalyses at the depth of intermediate water are more energetic and realistic than those in the CCSMs, which is attributed to the horizontal eddy-permitting resolution. The velocity fields and the transports in the Fram Strait are also investigated. The necessity of finer horizontal resolution is concluded again. The northward volume transports are much larger in the two reanalyses, although they are still weak comparing with mooring observations. Finally, an investigation of the impact of assimilation is done with an evidence of the heat input from assimilation. It is thought to be a reason for the good performance in the SODA, while the GLORYS drifts dramatically without assimilation data in the Arctic Ocean.

Keywords: Arctic Intermediate Water; model evaluation; Arctic modeling; impact of data assimilation

来源出版物:Acta Oceanologica Sinica, 33(12): 1-14联系邮箱:SU Jie, sujie@ouc.edu.cn

生物物理学

封面介绍:病毒给人类的健康和生命造成了巨大的威胁和灾害,例如人们熟知的肝炎病毒、艾滋病病毒、禽流感病毒、埃博拉病毒等,可以说这些小小的病毒可能是人类在生物界中最可怕的敌人.同时,病毒存在的范围很广,几乎所有的生物体中都发现有病毒,因此,人类可以利用病毒防治一些有害生物,称为生物防治.此外,病毒又是最简单、最微小的有机体,能够明显地体现出生物物质的特性,如生长增殖、遗传变异及相关的进化过程,等等,所以,病毒本身也是研究生命现象和了解生命本质的极好研究材料.然而,病毒太小了,甚至用显微镜也看不到它,以至于在很长一段时间里,人们认为它是某种致病因子.直到用电子显微镜直接观察到病毒后,才把它看成实在的生物体,但深入的研究仍然困难重重.20多年前出现的冷冻电镜技术(cryo-EM),由于适合于较大生物大分子复合物的结构解析,首先在病毒结构研究中获得应用.封面图片展示的是应用冷冻电镜技术解析出的质多角体病毒(CPV)近原子分辨率(0.39 nm)的结构.这是我国首次利用冷冻电镜技术解析的生物大分子近原子结构模型,也是目前国际上第一个处于转录进行状态的病毒的近原子分辨率结构.图中,圆圈内展示病毒转录后相关结构蛋白VP3 发生的张开和扭转等构象变化.这些构象变化及结构蛋白之间的相互协调作用,使得病毒新生RNA得以顺利流出.这一结构的解析为进一步认识RNA病毒的转录机制,干预病毒自我复制提供了结构基础.(综述,柳正等,pp.405-415)

结构生物学研究方法的重大突破——电子直接探测相机在冷冻电镜中的应用进展

柳正,张景强

摘要:近年来,科学家应用冷冻电镜技术(cryo-EM)解析出了低对称性生物大分子的高分辨率(3~5 Å)三维结构,并用其密度图直接进行了分子建模.与传统的X-射线和NMR方法相比,冷冻电镜技术具有适用于分子量较大的生物分子、样品不需结晶且用量很少等优势.尤其是电子直接探测相机(electron direct detection device,DDD)在冷冻电镜技术中的应用,使高分辨率的结构研究变得更加简单、应用更为广泛,是一个重大突破.文章介绍DDD相机的原理和技术优势,及其在解决冷冻电镜技术困难中的一些应用,进而展望了DDD相机可能给冷冻电镜技术应用带来的突破性进展.

关键词:冷冻电镜;电子直接探测相机;低对称生物大分子;高分辨率

来源出版物:生物物理学报, 2014, 30(6): 405-415联系邮箱:张景强,lsszhjq@mail.sysu.edu.cn

微生物学

封面介绍:The cytotoxicity ration of culture supernatant from different strains toward cancer cells B16 andHeLa. A, J: MD1 culture medium; B, K: S8; C, L: S20; D, M: S22; E, N: S34; F, O: S47; G, P: S51; H, Q: S55; I, R: S68. The scale bar, 100 µm.

土壤样品中粘细菌的分离鉴定及其生物活性检测

肖蓉,文也,唐少军,等

摘要:目的:从土壤样品中分离粘细菌,对其进行纯化、归类与鉴定,以丰富粘细菌菌种资源;对纯化得到的粘细菌进行抑菌、杀虫及抗肿瘤生物活性的分析,为粘细菌次级代谢产物的开发奠定基础.方法:采用灭活大肠杆菌和滤纸片诱导子实体法从土样中分离粘细菌,结合形态观察、生理生化特征和16S rDNA基因序列同源性分析,对分离到的各菌株进行鉴定并归类.通过平板扩散法、昆虫口服毒性测试、肿瘤细胞毒性实验等方法,检测粘细菌代谢产物生物活性.结果:共分离得到35株粘细菌,初步分类为:粘球菌属(Myxococcus)9株;珊瑚球菌属(Corallococcus)9株;侏囊菌属(Nannocystis)11株;堆囊菌属(Sorangium)6株.从其中纯化得到8株粘细菌,对其进行了鉴定并命名.发现了具有高效且广谱的肿瘤细胞毒性效应菌株S22,S51和S55也具同样的细胞毒性;另外,结果还发现具有肿瘤细胞毒性的S20,S22还对枯草芽胞杆菌和白色念珠菌具有较好的抑菌活性.结论:土壤中存在丰富的粘细菌资源,发现了具有肿瘤细胞毒性的弱小珊瑚球菌与具有抑菌和强抗肿瘤活性的大孢珊瑚球菌,粘细菌是活性天然产物与新药开发的重要资源.

关键词:粘细菌;分离鉴定;生物活性

来源出版物:微生物学报, 2014, 54(12): 1429-1437联系邮箱:孙运军,sunyj@hunnu.edu.cn

动物学

封面介绍:In a natural subalpine area in the Colorado Rocky Mountains, mule deer Odocoileus hemionus modify their anti-predator behavior as a function of distance to a seasonally active field station. Price et al. found that deer fled approaching humans and engaged in more active flight and anti-predator behavior when greater than 250-750 m from cabins. The concept of a spatial human footprint may help us better understand how to quantify human impacts on wildlife. See Mary V. PRICE et al., Pp 693-699. Photo by Lawrance Chung.

Human activity affects the perception of risk by mule deer

Mary V. PRICE, Evelyn H. STROMBOM, Daniel T. BLUMSTEIN

Abstract: Human activity has been shown to influence how animals assess the risk of predation,but we know little about the spatial scale of such impacts. We quantified how vigilance and flight behavior in mule deer Odocoileus hemionus varied with distance from an area of concentrated human activity—a subalpine field station. An observer walked trails at various distances away from the station looking for deer. Upon encounter, the observer walked toward the focal animal and noted the distance at which it alerted and directed its attention to the approaching human(Alert Distance; AD), and the distance at which it fled(Flight Initiation Distance; FID). AD and FID both increased nonlinearly with distance from the center of the field station, reaching plateaus around 250 m and 750 m, respectively. Deer also tended to flee by stotting or running, rather than by walking, when far from the station but they walked away when near the station. These results indicate that deer perceive lower risk near a focused area of human activity,and that vigilance and flight behaviors respond on somewhat different spatial scales. The concept of a spatial “human footprint” on behavior may be useful for understanding how human activities affect wildlife.

Keywords: Flight initiation distance; Alert distance; Predation risk assessment; Human disturbance; Mule deer; Odocoileus hemionus; Vigilance

来源出版物:Current Zoology, 2014, 60(6): 693-699联系邮箱:Daniel T. BLUMSTEIN, marmots@ucla.edu

Duchenne型肌营养不良小鼠模型鉴定及干细胞移植后dystrophin的变化

庞荣清,李自安,阮光萍,等

摘要:目的:建立Duchenne型肌营养不良(DMD)模型dko小鼠的鉴定方法,评估干细胞移植后dystrophin的再生水平.方法:采用SSP-PCR方法鉴定杂合子鼠交配产生的子代鼠的基因型.生化分析仪测定dko小鼠血浆肌酸激酶含量,HE染色观察肌肉组织学变化.扩增人脐带间充质干细胞并注射到dko小鼠后肢肌肉,2个月后免疫荧光染色法检测dystrophin的表达.结果:杂合子鼠交配可以产生三个基因型的子代鼠,21.2%的子代鼠可以鉴定为dko小鼠的基因型(285 bp).dko小鼠显示了肌营养不良的症状,血浆肌酸激酶含量高达(16988.52±617.48)IU/L,典型的病理变化包括肌纤维大小不一,多见核中移细胞,结缔组织增生或炎性细胞浸润.将人脐带间充质干细胞注射到dko小鼠后肢肌肉,2个月后可检测到人dystrophin的表达.结论:采用SSP-PCR可用于鉴定dko小鼠基因型,dko小鼠是研究干细胞治疗DMD的理想动物模型.

关键词:Duchenne型肌营养不良;动物模型;基因型鉴定;干细胞治疗;Dko小鼠

来源出版物:中国实验动物学报,2014, 22(6): 81-84联系邮箱:张永云,zyypang@126.com

昆虫学

封面介绍:The power of the small honeybee brain carrying out learning and memory tasks has been shown to be highly impressive. In this study, the authors analyzed the changes in micro-RNA and mRNA following maze-based visual learning using next-generation small RNA sequencing and Digital Gene Expression tag profiling. The results suggest that both microRNA and mRNA may play a pivotal role in the process of visual learning(see pages 619-636). Photo by Yun-Bo Xue.

The integrative analysis of microRNA and mRNA expression in Apis mellifera following maze-based visual pattern learning

Qiu-Hong Qin, Zi-Long Wang, Liu-Qing Tian, et al.

Abstract: The honeybee(Apis mellifera)is a social insect with strong sensory capacity and diverse behavioral repertoire and is recognized as a good model organism for studying the neurobiological basis of learning and memory. In this study, we analyzed the changes in microRNA(miRNA)and messenger RNA(mRNA)following maze-based visual learning using next-generation small RNA sequencing and Solexa/lllumina Digital Gene Expression tag profiling(DGE). For small RNA sequencing, we obtained 13 367 770 and 13 132 655 clean tags from the maze and control groups, respectively. A total of 40 differentially expressed known miRNAs were detected between these two samples, and all of them were up-regulated in the maze group compared to the control group. For DGE, 5 681 320 and 5 939 855 clean tags were detected from the maze and control groups,respectively. There were a total of 388 differentially expressed genes between these two samples, with 45 genes up-regulated and 343 genes down-regulated in the maze group, compared to the control group. Additionally, the expression levels of 10 differentially expressed genes were confirmed by quantitative reverse transcription polymerase chain reaction(qRT-PCR)and the expression trends of eight of them were consistent with the DGE result, although the degree of change was lower in amplitude. The integrative analysis of miRNA and mRNA expression showed that, among the 40 differentially expressed known miRNAs and 388 differentially expressed genes, 60 pairs of miRNA/mRNA were identified as co-expressed in our present study. These results suggest that both miRNA and mRNA may play a pivotal role in the process of learning and memory in honeybees. Our sequencing data provide comprehensive miRNA and gene expression information for maze-based visual learning, which will facilitate understanding of the molecular mechanisms of honeybee learning and memory.

Keywords: Apis mellifera; Y-maze; learning and memory; microRNA; DGE; differential expression

农业基础科学

来源出版物:Insect Science, 2014, 21(5): 619-636

封面介绍:2D-DIGE scanning results of total leaf protein of therice lesion mimic mutant chl1.

描述:经扫描仪扫描后得到用Cy2(蓝色)、Cy3(绿色)、Cy5(红色)标记总蛋白的2D-DIGE图像(图1).通过DeCyder 2D 7.0软件对chl1及其野生型的叶片总蛋白的2D-DIGE图像进行分析.

一个抗病性增强的水稻类病变突变体的蛋白质组学研究

韩雪颖,杨勇,余初浪,等

摘要:水稻类病变突变体chl1具有抗病性增强的类病变表型,对水稻白叶枯病和稻瘟病都具有很强的抗性.利用蛋白质组学技术分析chl1与其野生型之间的差异表达蛋白,探讨chl1类病变表型的形成和抗病反应的分子机制.利用荧光双向差异凝胶电泳(two-dimensional fluorescence difference gel electrophoresis, 2D-DIGE)技术和质谱分析,chl1中共鉴定到70个差异表达的蛋白点,包括46个上调蛋白点和24个下调蛋白点.这些蛋白点参与不同的生物过程,包括防御相关、光合作用、氧化还原、氨基酸/蛋白质代谢、分子伴侣、碳水化合物代谢.对这些差异表达蛋白进行生物信息分析,推测它们所在的复杂调控网络可能参与chl1叶片细胞程序性死亡(programmed cell death, PCD)及其抗病性的调控.

关键词:水稻;类病变突变体;细胞程序性死亡;抗病性;荧光双向差异凝胶电脉

来源出版物:中国水稻科学, 2014, 28(6): 559-569联系邮箱:陈剑平,jpchen2001@126.com

矿业工程

封面介绍:矿山岩体介质深埋于地下,传统的现场探测技术与实验方法难以准确地获知与直观表征地下开采引发的岩体介质内部孔/裂隙结构演化、应力重分布、流体渗流等“看不见、摸不着”的物理力学过程.数值模拟具有直观、定量、可重复、可预测和低成本等优势,成为解决上述难题的有力工具,但由于模型相似性、材料属性确定、特别是模拟结果难以验证等问题,岩体力学行为数值分析存在普遍争议.鞠杨课题组采用CT成像、三维重构和3D打印技术制备了深部天然裂隙煤岩的物理模型,结合应力冻结方法,研究了定量表征煤岩内部复杂裂隙结构与应力场的可视化方法,为实现地下岩体变形破坏及内部物理力学机制的定量表征与可视化以及验证数值分析探索了一条新路.封面展示了深部煤矿开采工作面、煤岩的数字模型和3D打印模型,它们清晰地显示了煤岩内部的天然裂隙结构与应力场分布.详见鞠杨等人文(p3109).

基于3D打印技术的岩体复杂结构与应力场的可视化方法

鞠杨,谢和平,郑泽民,等

摘要:准确表征与直观显示岩体复杂的内部结构与应力场是解决诸多地下工程问题的基础和关键.本文运用CT成像、三维重构和3D打印技术制备了包含复杂裂隙的天然煤岩模型,借助三维应力冻结和光弹技术,直观定量地显示了单轴压缩载荷作用下复杂裂隙煤岩内部的应力场分布特征.研究表明:通过3D打印技术制备的煤岩模型具有与天然煤岩一致的裂隙结构特征;3D模型的单轴抗压强度、弹性模量和泊松比等力学性能指标接近于天然裂隙煤岩;在不连续裂隙周边的高应力分布区域以及应力级差等方面,3D模型的实验结果与数值模拟结果具有较好的一致性;该方法能够直观定量地显示不连续不规则裂隙对煤岩的强度、变形以及应力集中区的影响.3D模型打印与应力冻结技术相结合为实现地下岩体内部复杂结构与三维应力场分布的定量表征与可视化,以及印证数值模拟结果提供了新途径.

关键词:裂隙岩体;3D打印;裂隙结构模型;应力场;可视化

来源出版物:科学通报, 2014, 59(32): 3109-3119联系邮箱:鞠杨,juy@cumtb.edu.cn

化学工业

封面介绍:A one-step continuous synthesis route of phenol by hydroxylation of benzene with hydrogen peroxide over ultrafine TS- in a submerged ceramic membrane reactor is developed. The operation conditions have important impacts on the benzene conversion, phenol electivity and filtration resistance. The optimum operation conditions can be obtained by balancing their effects on the catalytic properties and separation efficiency. The benzene hydroxylation with hydrogen peroxide over TS-1 can be continuously run over 20 h in the submerged ceramic membrane reactor and the ceramic membrane exhibits excellent stability in the reaction system(see Jiang et al. Pages 1199-1207).

One-step Continuous Phenol Synthesis Technology via Selective Hydroxylation of Benzene over Ultrafine TS-1 in a Submerged Ceramic Membrane Reactor

Hong Jiang, Fei She, Yan Du, et al.

Abstract: A newroute towards phenol production by one-step selective hydroxylation of benzenewith hydrogen peroxide over ultrafine titaniumsilicalites-1(TS-1)in a submerged ceramic membrane reactorwas developed, which can maintain the in situ removal of ultrafine catalyst particles fromthe reaction slurry and keep the process continuous. The effects of key operating parameters on the benzene conversion and phenol selectivity, as well as themembrane filtration resistance were examined by single factor experiments. A continuous reaction process was carried out under the obtained optimumoperation conditions. Results showed that the systemcan be continuously and stably operated over 20 h, and the benzene conversion and phenol selectivity kept at about 4% and 91%, respectively. The ceramic membrane exhibits excellent thermal and chemical stability in the continuous reaction process.

Keywords: Phenol; Benzene hydroxylation; TS-1; Submerged membrane reactor; Ceramic membrane

来源出版物:Chinese Journal of Chemical Engineering, 2014, 22(11/12): 1199-1207联系邮箱:Rizhi Chen, Rizhichen@163.com

封面介绍:Absorption spectra of samples G0, G0' and G2,shows the electron absorption cut-off edge(λabs)of the Sm3+singly-doped glass(G0’)is located in the UV spectral region, which is clearly red shifted, compared to the Sn2+singly-doped sample(G0)and the Sn2+/Sm3+co-doped sample(G2). Excitation(dash line)and emission(solid line)spectra of samples G0(λem=421 nm,λex=267 nm), G0'(λem=598 nm, λex=402 nm), and G2(λem=598 nm, λex=267 nm), shows the possible energy transfer(ET)process.Emission spectra of samples G1-G3(λex= 267 nm), shows the emission spectra of Sn2+/Sm3+co-doped samples(G1-G5)to evidence the proposed ET process from Sn2+to Sm3+. Emission spectra of samples G2, G4, G5(λex= 267 nm), Sm3+emission steadily increases with increasing Sn2+concentration from 0.50% to 2.00%, and the peak at 402 nm remains unchanged due to the presence of the constant Sm2O3content(i.e., 0.50%). The ET process from Sn2+to Sm3+occurs in the co-doped samples can be evidenced by theresults above.

锡/钐共掺磷酸盐玻璃的可控发光以及能量传递

闫志文,佟宇,蒋奇,等

摘要:通过激发光谱、荧光光谱以及荧光寿命测试,系统地研究Sn2+、Sm3+单掺以及Sn2+/Sm3+共掺磷酸盐玻璃的发光性能.在共掺样品的发射光谱中观察到1个涵盖蓝、绿、红色波段的超宽发光带,并可通过调节Sn2+/Sm3+浓度比实现对样品发光的调控.结果表明:在紫外光激发下,能量可由Sn2+传递给Sm3+,能量传递效率最高可达42%.通过Sn2+与Sm3+的能级图研究了能量传递的机理,同时计算了不同浓度Sn2+/Sm3+的共掺样品的色坐标.

关键词:磷酸盐玻璃;锡/钐共掺;光致发光;能量传递

来源出版物:硅酸盐学报, 2014, 42(11): 1468-1773联系邮箱:曾惠丹,hdzeng@ecust.edu.cn

(编辑张保清)

封面介绍:Spartina salt-marshes are widely distributed along the eastern China coastlines, which are created by a single species introduced into the region artificially three decades ago. Depending on the geographic conditions, the colonization of Spartina has varied influences on the coastal wetland environment and ecosystem. For more details see the research paper by GAO Shu et al. on pages 2567-2586.

Environment-ecosystem dynamic processes of Spartina alterniflora saltmarshes along the eastern China coastlines

GAO Shu, DU YongFen, XIE WenJing, et al.

Spartina alterniflora is ecologically important in its original habitat; however, it has caused controversy since it was introduction into China(now it has been spreading rapidly on the Jiangsu, Shanghai, Zhejiang and Fujian coasts). The purpose of the present contribution is, on the basis of an analysis and synthesis of existing data sets, to evaluate the environmental-ecological effects of S. alterniflora, and to identify the relevant scientific problems that require further research in the future. Investigations have shown that, by reducing the near-bed shear stress associated with tidal currents, S. alterniflora can enhance the settling flux of suspended sediment and deposition rate on the tidal flats over the region. Further, field survey and analysis indicate that the S. alterniflora salt-marsh has a high primary production and provides a new type of habitat for the native benthic fauna. Some macro-, meioand micro-fauna that used to live in the native salt-marshes have adapted to the S. alterniflora salt-marsh, forming a new ecosystem. Under the influences of a number of background factors, such as latitude variations and the coastal type, the environmental-ecological changes induced by Spartine have regional differentiations. To the north of Hangzhou Bay, with a high position of the pre-Holocene stratum base, a large width of the tidal flats, and a gentle bed slope, only a small part of the intertidal zone is occupied by the S. alterniflora salt-marsh. Here, the S. alterniflora salt-marshes mainly play a positive role in coastal protection and ecosystem functioning. In contrary, to the South of Hangzhou Bay, The pre-Holocene deposits are situated in relatively deeo waters, and the width of the tidal flats formed within coastal embayments is relatively narrow. As such, the expansion of S. alterniflora has squeezed the living space of other intertidal organisms, thus has a negative ecological effect. Therefore, the regional differentiation of the Spartina effects should be sufficiently considered in coastal development and management.Furthermore, in order to predict the future evolution of the S. alterniflora wetlands over the region, in addition to in situ monitoring and measurements, an ecosystem dynamic model should be established, taking into account the coupling of the rerrestrial and marine environmental-ecological processes.

tectonics; magmatic rocks; magmatic activity; continental dynamics; South China Block

猜你喜欢

可见
在“可见”与“不可见”之间:微信运动中的个体生活与数字交往
在“可见”与“不可见”之间:微信运动中的个体生活与数字交往
基于卷积降噪自编码器的苹果树种鉴别模型研究
稳定同位素、矿质元素及可见-近红外光谱技术在禽制品真实性鉴别中的应用研究进展
让思维“可见”
以身作则,做“可见”的德育
应用型本科院校“可见、可触摸式”文化体验模式研究及实践
关于融合社区资源,开发幼儿园生活化游戏场的文献综述
应用型本科院校“可见、可触摸式”文化体验模式研究及实践
从“可见”的女性到生命意识的多元化表达
——新中国成立70周年女性题材电影思考