鳜鱼视觉特性及其对捕食习性适应的研究III．视觉对猎物运动和形状的反应

作者采用行为学方法测定了伏击型凶猛鱼类鳜鱼视觉对猎物运动和形状特征的反应特性。鳜鱼对３种不同体形饵料鱼有最强的跟踪反应和攻击反应，对虾则有较强的跟踪反应而几乎没有攻击反应，对蜻蜒幼虫仅有不强的跟踪反应而完全没有攻击反应。它对低速（ｖ≤５ｃｍ／ｓ）一连续和等间歇不连续运动的饵料鱼有较强的跟踪反应和攻击反应，对中速和高速（ｖ≥１０ｃｍ／ｓ）连续运动的饵料鱼有最强的跟踪反应而几乎没有或完全没有攻击反应，对中速和高速等间歇不连续运动的饵料鱼则有最强的跟踪反应和最强的攻击反应。它对不连续运动的ａ、ｂ、ｃ、ｄ、ｅ、ｆ

Simultaneous determination of chromium(VI) and chromium(III) of bioavailable fraction in bottom mud by flow injection-atomic absorption spectroscopy

A rapid and sensitive method for separation and determination of Cr(VI) and Cr(III) in bottom mud of lake by flow injection on-line preconcentrtion system and GFAAS was developed. The available Cr(VI) and Cr(III) were extracted by HOAc or EDTA + NH4 NO3 and adsorbed simultaneously by an anion and a cation resin microclummn and then eluted simultaneously by 2 mol/L NH4 NO3 + 0.05 mol/L ascorbate and 2 mol/L H2SO4, respectively. The elution was performed for 50 s after adsorption for 2 min, and the efficiencies of elution were 85.4% - 94.8% and 96.7% - 106% for Cr(VI) and Cr(M) respectively. The detection limits of the method were 0.9 mu g/L and 2.7 mu g/L with relative standard deviations of 3.5% and 6.4% for the determination of Cr(VI) and Cr(III) in sample, respectively.

Photoreduction of mercuric salt in UV/Fe (III)-oxalate complex system

In this paper, the photochemical reduction process of Hg (II) in aqueous solution containing ferric iron and oxalate (Ox) has been studied. Under the radiation of a low-pressure mercury lamp (lambda = 253.7 nm, 8W), Fe(III)-oxalate complexes undergo photolysis to produce ferrous ions and other organic reductive species, which reduce Hg(II) subsequently. For 0.1 mg/L Hg (II), the photoreduction efficiency is comparatively higher in the solution at pH 5.0 than that over the range of 3.0 similar to 8.0. The photoreduction efficiency of Ho (II) in aqueous solution increases with increasing, initial concentration of ferric ions from 0.02 mmol/L to 0.2 mmol/L and initial concentration of oxalate from 0.96 mmol/L to 4.8 mmol/L and then gradually approaches to a steady state. CH3OH also contributes the reduction of Hg (II). We investigate the increase of the ferric, oxalate and CH3OH concentrations resulting from the increase of reduction efficiency of Hg (II). It can be seen that ferrous ions and other reactive species are reductants of Hg (II), and the reaction product with oxalate is mainly volatile metallic mercury.

Study on fluorescence emission and synchronous-scan fluorescence spectrea of Nitzschia hantzschiana solution with FE(III)

The characterization of the algal Nitzschia hantzschiana solution with (or without) Fe(III) was carried out using fluorescence emission and synchronous-scan spectroscopy. An emission peak (excited at 440 nm) was observed at 675 nm for Nitzschia hantzschiana solution. The effective characterization method used was synchronous-scan fluorescence spectroscopy (SFS). A wavelength difference (Delta lambda) of 90 nm was maintained between excitation and emission wavelengths. The peak was observed at about 236(ex) nm (326(em) nm) for synchronous fluorescence spectroscopy. Fe(III) was an effective quencher. The relationship between I-0/I (quenching efficiency) and c (concentration of Fe (III) added) was a linear correlation for the algal solution with Fe(III). Effects of pH on synchronous-scan fluorescence intensity were evident.

Preliminary study on the photoproduction of hydroxyl radicals in aqueous solution with Aldrich humic acid, algae and Fe(III) under high-pressure mercury lamp irradiation

Under a high-pressure mercury lamp (HPML) and using an exposure time of 4 h, the photoproduction of hydroxyl radicals ((OH)-O-.) could be induced in an aqueous solution containing humic acid (HA). Hydroxyl radicals were determined by high-performance liquid chromatography using benzene as a probe. The results showed that (OH)-O-. photoproduction increased from 1.80 to 2.74 muM by increasing the HA concentration from 10 to 40 mg L-1 at an exposure time of 4 h (pH 6.5). Hydroxyl radical photoproduction in aqueous solutions of HA containing algae was greater than that in the aqueous solutions of HA without algae. The photoproduction of (OH)-O-. in the HA solution with Fe(111) was greater than that of the solution without Fe(III) at pH ranging from 4.0 to 8.0. The photoproduction of (OH)-O-. in HA solution with algae with or without Fe(111) under a 250 W HPML was greater than that under a 125 W HPML. The photoproduction of (OH)-O-. in irradiated samples was influenced by the pH. The results showed that HPML exposure for 4 h in the 4-8 pH range led to the highest (OH)-O-. photoproduction at pH 4.0.

Taxonomic studies of parasitic nyctotherans from chinese Anura amphibians III. Wichtermania

Wu-Han Xiao, Jian-Guo Wang and Lian-Xiang Li (2002) Taxonomic studies of parasitic nyctotherans from Chinese Anura amphibians III. Wichtermania. Zoological Studies 41(1): 69-76. This paper describes 6 new species belonging to the genus Wichtermania from Anura amphibians distributed in southern China. The 6 species are Wichtermania multigranularis sp. nov., W. oviformis sp. nov., W vesiformis sp. nov., W. reticulatis sp. nov., W granuliformis sp. nov., and W obliquoides sp. nov. The characteristics for diagnosis of the 6 new species are described in this paper.

LSIS-III VLSI CAD 系统集成的研究

Submitted by zhangdi (zhangdi@red.semi.ac.cn) on 2009-04-13T11:45:31Z

气态源分子束外延III-V族可见光半导体材料及其性质研究

Submitted by zhangdi (zhangdi@red.semi.ac.cn) on 2009-04-13T11:45:31Z

III-V半导体低维结构材料分子束外延生长及其性质的研究

Submitted by zhangdi (zhangdi@red.semi.ac.cn) on 2009-04-13T11:45:31Z

III-V族可见光半导体材料生长及其性质研究

Submitted by zhangdi (zhangdi@red.semi.ac.cn) on 2009-04-13T11:45:31Z

III-V族和碳杂质对硅中热施主的影响

Submitted by zhangdi (zhangdi@red.semi.ac.cn) on 2009-04-13T11:45:31Z

III-V族半导体的喇曼散射研究

Submitted by zhangdi (zhangdi@red.semi.ac.cn) on 2009-04-13T11:45:31Z

六角III-V氮化物量子阱的电子结构和光学性质

Submitted by zhangdi (zhangdi@red.semi.ac.cn) on 2009-04-13T11:45:31Z

III-V族半导体低维结构材料的平面光学各向异性

Submitted by zhangdi (zhangdi@red.semi.ac.cn) on 2009-04-13T11:45:31Z