Isoprene emission from tropical trees in Okinawa Island, Japan

This study surveyed isoprene emission from 42 indigenous and exotic tropical trees in subtropic Okinawa, Japan. Of the 42 trees studied, 4 emitted isoprene at a rate in excess of 20 μg g⁻¹ h⁻¹, and 28 showed the rates of 1–10 μg g⁻¹ h⁻¹. The remainder emitted less than 1 μg g⁻¹ h⁻¹. The majority of trees in this study may therefore fall within the lower emitting species. However, species in Moraceae that is indigenous in Okinawa emitted isoprene at relatively higher rates with an average of 14.2 μg g⁻¹ h⁻¹. The highest emission rate of 107.1 μg g⁻¹ h⁻¹ for Ficus virgata yielded the area basis rate of 47.4 nmol m⁻² s⁻¹, which is almost equivalent to the rate of high emitting species. Furthermore, a linear relationship between light intensity and isoprene emission was noted with Ficus virgata up to 1700 μmol m⁻² s⁻¹. These findings may show the potential importance of subtropical areas as sources of isoprene to the atmosphere.     

PCDD/PCDF formation in the chlor-alkali process—laboratory study and comparison with patterns from contaminated sites

Studies on the formation of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) during the electrolysis of sodium chloride solution (brine) using graphite or titanium electrodes were carried out at a laboratory scale. High concentrations of PCDFs but no PCDDs were formed in tests using graphite electrodes. With titanium electrodes, PCDFs were only formed when tar pitch was added and mainly originated from the dibenzofuran present in the tar. For the first time, a detailed assessment of the formation of mono- to octachlorinated PCDD/PCDF from tar pitch was investigated. The assessment included of the chlorination steps proved that PCDFs were formed by successive lateral chlorinated from dibenzofuran to MonoCDFs, DiCDFs, and TriCDFs to form the typical known “chlorine pattern” of TetraCDF to OctaCDF with a dominance of 1,2,7,8- and 2,3,7,8-TetraCDFs, 1,2,3,7,8-PentaCDF, and 1,2,3,4,7,8-HexaCDF as marker congeners. The final homologue distributions depended on reaction time and reaction temperature. In addition, electrolysis with non-chlorinated dibenzo-p-dioxins, dibenzofuran, and biphenyl was carried out. As a result, PCDDs, PCDFs, and PCB were formed at comparable yields. Congener patterns in soil samples from a PCDD/F-contaminated site where chlor-alkali electrolysis had been operated for decades in Japan had identical isomer distribution demonstrating the source and contamination potential and risk of these processes. Therefore, sites where in the past 120 years chlor-alkali electrolysis has been operated or where residues from chlor-alkali production or other chlorine using industries have been disposed should be assessed for their pollution level and exposure relevance. The assessment of total organohalogen content revealed that PCDF is only a small fraction of organohalogens in the contaminated soils. For an appropriate risk assessment, also other chlorinated aromatic compounds such as PCBs or PCNs need to be considered.     

土壤和沉积物中痕量元素的ICP质谱法测定

人们对环境中污染物 (特别是重金属 )的“安全”水平的关注与日俱增 ,要分析的元素更多 ,浓度更低 ,从而暴露出当前所用分析技术的局限性 ,需要进一步提高分析方法的灵敏度和可分析的元素数量 .尽管ＧＦＡＡＳ (石墨炉原子吸收光谱 )和ＩＣＰ ＯＥＳ (感耦等离子体发射光谱 )仍是环境元素分析中最常用的技术 ,但ＩＣＰ ＭＳ (等离子体质谱 )是具有更高灵敏度的分析技术 ,不久肯定会被普遍接受 .ＨＰ 4 50 0台式ＩＣＰ质谱仪具有实际惯常分析应用所必需的可靠性和易于操作 ,可进行亚ｎｇ·ｍｌ- 1级 (ｐｐｂ)浓度水平的多元素快速分析 .本篇…     

Growth inhibition and formation of morphologically abnormal cells of <Emphasis Type="Italic">Akashiwo sanguinea</Emphasis> (Hirasaka) G. Hansen et Moestrup by cell contact with <Emphasis Type="Italic">Cochlodinium polykrikoides</Emphasis> Margalef

We investigated the growth interaction between Cochlodinium polykrikoides and Akashiwo sanguinea using bi-algal cultures. When cultured together, morphologically abnormal cells of A. sanguinea appeared and the growth of A. sanguinea notably decreased. When C. polykrikoides and A. sanguinea were cultured separately in inner and outer wells separated by a membrane with a pore size of 3 μm, neither species showed suppressed growth and no morphologically abnormal cells of A. sanguinea were observed. Furthermore, filtrates from C. polykrikoides cultures did not affect the cell morphology or the growth of A. sanguinea. When the abnormal cells of A. sanguinea were transferred from bi-algal cultures into fresh medium and cultured as a mono-algal culture, cells recovered their normal morphology and multiplied. Therefore, the growth inhibition and formation of morphologically abnormal cells of A. sanguinea would be induced by constant cell contact with C. polykrikoides.     

Decomposition of poly(amide-imide) film enameled on solid copper wire using atmospheric pressure non-equilibrium plasma

The decomposition of a poly(amide-imide) thin film coated on a solid copper wire was attempted using atmospheric pressure non-equilibrium plasma. The plasma was produced by applying microwave power to an electrically conductive material in a gas mixture of argon, oxygen, and hydrogen. The poly(amide-imide) thin film was easily decomposed by argon-oxygen mixed gas plasma and an oxidized copper surface was obtained. The reduction of the oxidized surface with argon-hydrogen mixed gas plasma rapidly yielded a metallic copper surface. A continuous plasma heat-treatment process using a combination of both the argon-oxygen plasma and argon-hydrogen plasma was found to be suitable for the decomposition of the poly(amide-imide) thin film coated on the solid copper wire.     

二价铜离子与抗坏血酸共存下的杀菌效果及其机理

考察了二价铜离子与抗坏血酸的组合对大肠杆菌的杀菌效果。实验证明:高浓度的铜离子与抗坏血酸的组合有非常好的杀菌效果,不论是酸性还是中性条件下都能在0.5 h杀灭所有的大肠杆菌;低浓度的铜离子与抗坏血酸的组合也有不错的杀菌效果,且随着pH值的升高,杀菌效果增强,pH=4的条件下24 h后杀灭大肠杆菌,pH=7的条件下0.5 h便能杀灭所有杆菌。实验运用ESR检测羟基自由基,并结合杀菌实验结果推断二价铜离子与抗坏血酸反生了类Fenton反应。     

Gonadotropic effects of dopamine in isolated workers of the primitively eusocial wasp, Polistes chinensis

In social insects, biogenic amines are thought to play regulatory roles in the transition between reproductive states in females. To determine the effect of dopamine on the reproductive development of workers in primitively eusocial societies, isolated workers of the paper wasp Polistes chinensis were supplied with oral dopamine. Ovarian development was accelerated in dopamine-fed workers as compared to control workers of the same age fed only sucrose solution. Oral dopamine increased brain levels of dopamine and its metabolite (N-acetyldopamine). Brain levels of tyramine or octopamine were also increased by dopamine application in one of two colonies; levels of the tyramine metabolite N-acetyltyramine were unchanged. These results indicate that dopamine plays a gonadotropic role in isolated workers in the primitively eusocial wasp, similar to the gonadotropic role previously reported for juvenile hormone. This is the first study to report effects of dopamine on ovarian development in workers of the paper wasp.     

土壤酸化及天然土壤溶液中铝的形态

采用真空式土壤溶液采样器收集了宜昌、巫山松树林中天然土壤溶液,采用高效液相色谱法Al－Lumogallion柱后荧光检测,分析测试了土壤溶液中可溶性铝的形态,研究了由于土壤酸化引起天然土壤溶液中不同形态铝的迁移转化结果表明,天然土壤溶液中含有不同形态的铝,主要是有机铝、 AISO₄⁺、AIF₂⁺、Al（OH）²⁺、Al³⁺等．宜昌、巫山地区土壤溶液中活性铝（Al³⁺、AlOH^2+F）的含量比较低．土壤的酸化使得天然土壤溶液中总铝含量增加、铝形态的优势态发生变化,即土壤的酸化使得天然土壤溶液中活性铝－Al³⁺、AlOHF²⁺含量和比例增加．土壤酸化还降低了大然土壤溶液中的BC/Al比值,这些变化的结果都增加了对森林潜在的危害．     

Low-pressure reverse osmosis as a process for treatment of anionic pollutants in water environment

The recent development of new generation Low-Pressure Reverse Osmosis (LPRO) or nanofiltration membranes have received attraction for application in the field of wastewater and water treatment through an increasingly stringent regulation for drinking purpose and water reclamation. In this research, the application on treatment of anionic pollutants (NO₃ ^-, NO₂ ^-, Cl^-, SO₄ ^2- &; H₂PO₄ ^-) was done under very much lower pressure range of operation (0.49 to less than 0.1 MPa) than any other previous research has done. Moreover, the extended Nernst-Planck equation was used for analysis of the experimental data by considering effective charge density of the membranes.