Light-induced conversion of an insulating refractory oxide into a persistent electronic conductor

Materials that are good electrical conductors are not in general optically transparent, yet a combination of high conductivity and transparency is desirable for many emerging opto-electronic applications. To this end, various transparent oxides composed of transition or post-transition metals (such as indium tin oxide) are rendered electrically conducting by ion doping. But such an approach does not work for the abundant transparent oxides of the main-group metals. Here we demonstrate a process by which the transparent insulating oxide 12CaO x 7Al(2)O(3) (refs 7-13) can be converted into an electrical conductor. H(-) ions are incorporated into the subnanometre-sized cages of the oxide by a thermal treatment in a hydrogen atmosphere; subsequent irradiation of the material with ultraviolet light results in a conductive state that persists after irradiation ceases. The photo-activated material exhibits moderate electrical conductivity (approximately 0.3 S cm(-1)) at room temperature, with visible light absorption losses of only one per cent for 200-nm-thick films. We suggest that this concept can be applied to other main-group metal oxides, for the direct optical writing of conducting wires in insulating transparent media and the formation of a high-density optical memory.     

二成分混合流体Rayleigh-Benard对流

Rayleigh-Benard(RB)对流是研究非平衡对流的稳定性、非线性动力学特性及湍流形成机理的典型模型之一。在介绍RB对流研究方法的基础上，论述了其最新研究进展：混合流体RB对流运动的稳定性及其非线性动力特性；RB对流与水平流动相耦合时的非线性动力特性。最后提出了有待进一步研究和探讨的问题。     

新型金属一体化催化剂在甲烷催化燃烧中的性能

以Clad芯材铝板(Al/Alloy/Al)为原材料,利用铝的阳极氧化技术制备出新型金属一体化阳极氧化-γAl2O3载体。并利用这种载体采用浸渍法制备了Pt/Al2O3/Alloy、Pd/Al2O3/Alloy及Pd-Pt/Al2O3/Alloy催化剂,考察了各催化剂在甲烷燃烧中的性能。结果表明:低温下(<500℃)Pt/Al2O3/Alloy催化剂活性较差,而在高温下(>700℃)Pd/Al2O3/Alloy催化剂容易失活。向Pd/Al2O3/Alloy催化剂中加入一定量的Pt后(Pd-Pt/Al2O3/Alloy),明显提高了PdO的分解温度,从而提高了催化剂的活性及稳定性。     

Development of antral gastrin-like immunoreactivity and pituitary CCK8/gastrin-like immunoreactivity in rats

Summary Gel filtration of antral extract of adult rats revealed gastrin-17 and gastrin-34. Gel filtration of anterior pituitary extract showed CCK8 and gastrin-17, whereas posterior pituitary extract showed only a CCK8. Antral gastrin-like immunoreactivity (G-LI) increased after milk feeding and especially after weaning was started. Changes in diet may exert a profound influence on the ontogenic development of antral G-LI, but not pituitary CCK8/G-LI.     

对虾白斑症病毒(WSSV)对蟹类的感染

在对虾白斑症病毒(WSSV)病发生期间,养殖虾池内的蟹类也往往出现异常甚至死亡．通过WSSV对三疣梭子蟹(Portumus trituberculatus)的人工感染证实了其感染性．三疣梭子蟹在注射感染后第9天全部死亡,注射后第6天死亡率最高;经口感染,三疣梭子蟹在感染后第25天全部死亡,在15～20d死亡率最高;在浸洗感染和对照组30d内无蟹子死亡．在感染死亡蟹子和发病虾池内病蟹的鳃、上皮组织的细胞核内电镜观察到的病毒粒子,其形态特征与在对虾上观察到的一样．用PCR和单克隆抗体的FAT法在注射感染和投喂感染的蟹子都得到了WSSV感染阳性结果,浸浴感染的蟹子和健康蟹子都得到了WSSV感染阴性结果．蟹类(三疣梭子蟹)对WSSV的敏感性较对虾低,为此蟹类有可能是WSSV的携带者或传播者．     

Phylogeography of the Eurasian red squirrel (Sciurus vulgaris orientis) on the boreal island of Hokkaido,Japan

To test postglacial population expansion in small arboreal mammals dependent on boreal and subboreal forests, we used complete mitochondrial cytochrome b gene sequences (1140 bases) to investigate the phylogeography of the Eurasian red squirrel (Sciurus vulgaris orientis) on the Hokkaido Island of Japan. This subspecies is common in the boreal and subboreal forests of Hokkaido. We examined 61 specimens from 27 localities in Hokkaido. Phylogenetic relationships among 29 haplotypes found in the Hokkaido populations were not associated with geographic distribution of sampling localities. There were four mitochondrial DNA phylogroups. Phylogeographic analyses support sudden expansion of S. vulgaris orientis from restricted refugium in the southern part of Hokkaido during the last glacial period. The phylogeographic structure of this subspecies directly reflects the boreal and subboreal forest dynamics occurring in Hokkaido.     

MnCuOx／Al2O3催化剂上的催化燃烧及其动力学研究

研究了用于挥发性有机化合物催化燃烧的金属与催化层一体化催化剂，探讨了孔径对催化剂性能的影响。根据Ｌａｎｇｍ ｕｉｒ吸附理论，建立了催化燃烧反应动力学模型，得到了甲苯、二甲苯、环己烷在空气中催化燃烧反应动力学方程。     

Development of antral gastrin-like immunoreactivity and pituitary CCK8/gastrin-like immunoreactivity in rats

Gel filtration of antral extract of adult rats revealed gastrin-17 and gastrin-34. Gel filtration of anterior pituitary extract showed CCK8 and gastrin-17, whereas posterior pituitary extract showed only a CCK8. Antral gastrin-like immunoreactivity (G-LI) increased after milk feeding and especially after weaning was started. Changes in diet may exert a profound influence on the ontogenic development of antral G-LI, but not pituitary CCK8/G-LI.