Sulfur Metabolism in Polluted Sphagnum Peat Bogs: A Combined 34S–35S–210Pb Study

The size and isotopic behavior of sulfur pools in²¹⁰Pb-dated peat cores were investigated to obtain aninsight into retention mechanisms of pollutant S in twomountain-top peatlands of the Northern Czech Republic, CentralEurope. The bogs were situated 40 km apart in an area whichbetween the years 1985 and 1995 received as much as 130 kg Sha^-1 yr^-1 from the atmosphere. Vertical peataccretion was faster at Pod Jelení horou (JH) than atVelký moál (VM). Organic carbon-bonded S was themost abundant sulfur pool, constituting 77 and 65 wt. % at JHand VM, respectively. At JH both the S concentration maximumand the highest annual S deposition rate were displaceddownward by more than 20 years (from 1987 to the 1960s)indicating that the buried S is vertically mobile. At VM the Sconcentration was the highest in the topmost 2-cm section eventhough atmospheric S deposition peaked in 1987. Differentmechanisms of S isotope redistribution prevailed in thetopmost peat layers at JH, where a negative ³⁴Sshift occurred, and at VM, where a positive ³⁴Sshift occurred. Bacterial sulfate reduction was responsiblefor the negative ³⁴S shift at JH. One possibleexplanation of the positive ³⁴S shift at VM isrelease of ³²S-enriched products of mineralization duringpeat diagenesis. There was a strong positive correlationbetween the abundance of total and pyrite S along the profiles.The presence of pyrite S at VM (526 ± 60 ppm) suggestedthat even at VM bacterial sulfate reduction occurred. Ananaerobic incubation of JH peat indicated sulfate reductionrate of 600 nmol g^-1 day^-1. The turnover times forinorganic S pools were shorter than for the organic S pools.Cumulative S contents in the Czech peat bogs were found to besignificantly lower than in similar sites in the NortheasternU.S., even though the atmospheric S inputs were more thanthree times higher at the Czech sites. Possible causes of suchdiscrepancy are discussed.     

社区居民参与的激励因素——"周庄现象"的思考

从对“周庄现象”的思考提出了为实现旅游可持续发展而激励旅游地居民参与的两种因素——物质激励因素及非物质激励因素，分析了两种激励因素的运用与作用机理，认为激励手段的使用要根据旅游地的发展阶段有重点地确定，这样才能激发旅游地居民积极参与到旅游业的发展中去。     

湖南传统村落的防御性特征

防御性在中国传统村落的规划和建设中具有很高的研究价值。通过分析湖南传统村落在选址、空间形态、防火和建筑装饰等方面的防御性特征,指出传统村落的物质防御和精神防卫等防御理念具有明显的先进性与科学性。两个方面共同作用,所营造的传统村落的安全居住环境,是中国传统文化因素中的心理安全防御意识在具体环境中的物化体现,是中国传统哲学观念和生态环境观念的有机统一,指出传统村落的防御性在当今和谐社会宜居社区的规划和建设中的借鉴意义。     

Book Reviews

Books reviewed:
Thomas Drabek, Disaster-induced Employee Evacuation
Hugh Brammer, Agricultural Disaster Management in Bangladesh
Boris Porfiriev, Disaster Planning and Emergency Management in Russia
Patrick Bracken and Celia Petty, eds, Rethinking the Trauma of War
R. Cohen and F. M. Deng, eds, The Forsaken People: Case Studies of the Internally Displaced
Tom Trier and Lars Funch Hansen, eds, Conflict and Forced Displacement in the Caucasus: Perspectives, Challenges and Responses     

人为泥石流起动及产沙放水冲刷实验——以神府-东胜矿区为例

神府东胜矿区位于黄土高原北部干旱半旱过度地带。由于煤田的大量开采，诱发了大量的环境问题，尤以人为泥石流最为严重，本文以神府－东胜矿区人为泥石流为研究对象，采用人工放水冲刷模拟的方法，分析了坡面型和沟谷型泥石流源地松散体起动、产沙、泥石流过程的特性，所得结论为：（１）放水历时长，强度大，有利于泥石流的形成；（２）弃土石渣起动，是该区泥石流固体物质的主体；（３）沟道型泥石流放水冲刷模拟实验，便于观测石     

炭催化剂吸附剂标准物质的研制

本文介绍了炭催化剂吸附剂标准物质的研制过程。对标准物质的制备技术、均匀性检验、稳定性考察及定值和不确定度进行了逐项分析。采用活性炭浸渍、煅烧技术制得炭催化剂吸附剂标准物质。试验结果表明，该标准物质定值结果准确，均匀性、稳定性良好。铜含量的标准值为11．06％，扩展不确定度为0．13％。     

Benzoic acid, a stimulant of odorant receptors of Bombyx mori, is rapidly metabolized to N-benzoylserine on the antennae

Summary. Benzoic acid is a known stimulant of olfactory receptor cells in trichoid sensilla on the antennae of adult females of Bombyx mori. Exposure of freshly excised antennae, from B. mori females and males, to vapours of [¹⁴C]-benzoic acid revealed that the adsorbed acid is rapidly metabolized (15% conversion in 10 s), suggesting the presence of a highly active enzymatic system. The major product could be identified as N-benzoylserine by use of [²H₅]-benzoic acid, and mass spectrometry linked to a gas chromatograph (GC-MS) or a liquid chromatograph (LC-MS), for analysis of the metabolites. The conjugation of benzoic acid with an amino acid apparently represents a novel mode for the rapid deactivation of odorant molecules. Received 26 March 2001.     

联苯代谢对微生物的生长胁迫及分裂抑制

以联苯/多氯联苯降解菌株R04（Rhodococcus sp.R04）和几种模式微生物为研究对象，利用高效液相色谱、荧光显微镜、扫描电子显微镜等分析微生物在联苯及其代谢物培养条件下细胞分裂和形态的变化.结果表明联苯及其代谢产物对红球菌R04和几种模式微生物细胞的分裂有抑制作用，并对部分微生物形态有影响.与前体-联苯及其代谢产物2-羟基-6-酮基-6-苯基-2，4-己二烯酸相比，2，3-二羟基联苯对G⁺、G^-细菌，或是酵母细胞分裂都有较强的抑制和形态的改变.2，3-二羟基联苯导致R.R04和缺陷型R.R04细胞形成不完整隔膜的比例增加；造成96.4%的大肠杆菌BL21细胞表面凹陷，胞质内容物流失，菌体体积缩小；导致枯草芽孢杆菌89.6%的细胞体积明显缩小；导致金黄色葡萄球菌基本没有细胞能形成完整的分裂隔膜；导致红酵母细胞能进行出芽生殖的比例从64.2%降低到19.3%，但对其细胞形态无明显改变.联苯代谢物2，3-二羟基联苯对红球菌R04及其它微生物细胞分裂和增殖的抑制作用比其前体-联苯强，建议在研究环境化合物与微生物互作时，应考虑环境化合物代谢的毒性效应.     

Radon exhalation from building materials for decorative use

Long-term exposure to radon increases the risk of developing lung cancer. There is considerable public concern about radon exhalation from building materials and the contribution to indoor radon levels. To address this concern, radon exhalation rates were determined for 53 different samples of drywall, tile and granite available on the Canadian market for interior home decoration. The radon exhalation rates ranged from non-detectable to 312 Bq m⁻² d⁻¹. Slate tiles and granite slabs had relatively higher radon exhalation rates than other decorative materials, such as ceramic or porcelain tiles. The average radon exhalation rates were 30 Bq m⁻² d⁻¹ for slate tiles and 42 Bq m⁻² d⁻¹ for granite slabs of various types and origins. Analysis showed that even if an entire floor was covered with a material having a radon exhalation rate of 300 Bq m⁻² d⁻¹, it would contribute only 18 Bq m⁻³ to a tightly sealed house with an air exchange rate of 0.3 per hour. Generally speaking, building materials used in home decoration make no significant contribution to indoor radon for a house with adequate air exchange.     

Remediation of copper-contaminated topsoils from a wood treatment facility using in situ stabilisation

Five organic matters, three phosphate compounds, zerovalent iron grit (ZVIG, 2% by soil weight), two alkaline compounds, and two commercial formulations were incorporated, singly and some combined with ZVIG, into a highly Cu-contaminated topsoil (Soil P7, 2600 mg Cu kg⁻¹) from a wood treatment facility. Formulations and two composts were also singly incorporated into a slightly Cu-contaminated topsoil (Soil P10, 118 mg Cu kg⁻¹) from the facility surrounding. This aimed to reduce the labile pool of Cu and its accumulation in beans cultivated on potted soils in a climatic chamber. Lowest Cu concentration in soil solution occurred in P7 soils amended with activated carbon (5%) and ZVIG, singly and combined. Basic slag (3.9%) and compost of sewage sludge (5%) combined with ZVIG promoted shoot production and limited foliar Cu accumulation. For amended P10 soils, no changes occurred in soil solution and foliar Cu concentrations, but one compost increased shoot production.