有机氯农药六六六污染土壤的植物修复研究

我国20世纪六七十年代大量施用的有机氯农药,由于其性质极其稳定,在土壤至今仍有残留。植物修复有机农药污染土壤并不多见,但具有广阔的应用前景。此项研究对提高土壤环境质量、保证农产品的安全、实现农业可持续发展等有着重要的理论和现实意义。文章以多花黑麦草(Lolium multiforum Lan.)、紫花苜蓿(Medicago sativa L.)和籽粒苋(Amaranthus hypochondriacus L.)作为供试植物,在有机氯农药六六六(HCH)质量分数为1.09 mg.kg-1的污染土壤中种植3个月,研究了种植不同植物条件下土壤中HCH的消解情况。研究结果表明,与对照相比,种植植物大大提高了土壤中微生物数量和酶的活性,并且微生物的数量和酶的活性与土壤中HCH的消解密切相关。试验结束后,不同处理中HCH及其4种异构体的总含量降低幅度为43.87%~65.79%,其中种植紫花苜蓿和多花黑麦草的处理中HCH消解较快,对HCH污染土壤修复的效果较好。可见,植物修复技术是一种可行的环境友好的修复六六六污染土壤的技术。     

NF-κB and AP-1 as molecular targets for chemoprevention with EGCG, a review

There are multiple lines of compelling evidence, mostly from population-based studies, supporting that green tea consumption is associated with reduced risk of several human malignancies. Epigallocatechin gallate (EGCG) is a major antioxidant present in green tea. Chemopreventive effects of EGCG have been extensively investigated and well documented. These include inhibition of metabolic activation of carcinogens and/or stimulation of their detoxification, scavenging of reactive oxygen species, induction of apoptosis or differentiation of malignant or transformed cells, suppression of tumor promotion, inhibition of angiogenesis or metastasis, etc. EGCG targets many intracellular signaling molecules and events responsible for malignant transformation or abnormal cell proliferation, and NF-κB and AP-1 appear to be two of most potential targets of EGCG in its exerting chemopreventive activities.     

模拟酸雨对红壤铝形态的影响

用动态淋洗试验，研究了不同pH的模拟酸雨对红壤中铝形态和性质的影响．结果表明，酸雨淋洗引起红壤中盐基离子的淋失和土壤铝的溶出．随着酸雨溶液pH的降低，盐基淋矢量和铝溶出量增加．酸雨淋洗影响土壤铝形态的转化，使红壤中交换态铝上升，吸附态羟基铝有所下降．这说明在酸雨长期作用下，羟基铝溶解，并转化为交换态铝和引起铝的溶出，使铝进入环境，危害生态系统．     

Geochemical evidence of pollutants from coalfired generating stations in late Pleistocene palaeosols in the Dalijia Shan,northwestern China

Surface palaeosols in two tills and a diamicton from an area in northwestern China were analysed for geochemical pollutants. Elevated levels of Br, As and Sb indicate that pollution from coal-burning and/or coal-fired electricity generating stations is delivered by aeolian transport into palaeosols dating from the last glaciation. Because the climate in the field area is sub-humid (precipitation <760 mm) the relative movement of soluble elements in palaeosols dating from early and late stades of the last glaciation is not expected to be high. The glacial and aeolian parent materials of the palaeosols indicate differences that are probably related to their source areas and to the incorporation of geochemical pollutants.     

表面活性剂对可离子化有机化合物在黄土中吸附行为的影响

研究了2，4-二氯苯酚、2，4-二硝基苯酚和苯甲酸三种可离子化有机化合物在天然黄土和阳离子表面活性剂改性黄土中的吸附行为。讨论了DH值、离子强度和二价重金属阳离子对可离子化有机化合物在改性黄土中吸附的影响。提出了可离子化有机化合物在改性黄土中的吸附模型，吸附等温曲线可分解为两条分别代表离子和非离子形态的等温吸附曲线；其吸附行为可用双模式吸附理论来解释。在2，4-二硝基苯酚共存时，苯甲酸在改性黄土中的吸附量减小，证明竞争吸附的存在。     

Reconnaissance soil geochemical survey of Gibraltar

The extreme density of population of Gibraltar, situated at the southern tip of Spain, exerts considerable pressure on land use and thus future planning is of utmost importance. An initial reconnaissance soil geochemical survey of Gibraltar was based on 120 surface samples (0–15 cm) taken from a wide range of exposed, either bare soil or vegetated sites, to provide the optimum geographical distribution. The total elemental concentrations of 26 elements (Li, Na, K, Be, Mg, Ca, Sr, Ba, Al, La, Ti, V, Cr, Mo, Mn, Fe, Co, Ni, Cu, Ag, Zn, Cd, Pb, P, S, As) were determined by nitric/percholric acid digestion followed by inductively coupled plasma-atomic emission spectrometry (ICP-AES) analysis. The reconnaissance data shows that the spatial distribution of various elements depended on previous and present land use. Most elements (Ca, Cr, Mg and Mn excluded) exhibited relatively high concentrations in civilian and natural soils. Trends have been established for many elements, and concentrations exceeding guideline values have been found in certain areas of Gibraltar. This reconnaissance of Gibraltar is at present being followed by a more detailed baseline geochemical survey, which will establish the extent and magnitude of the variations in major and trace elements in soils and dusts, assess the impact of industrial, commercial and urban development on the geochemical landscape and to make recommendations concerning sustainable development.     

铝对茶叶叶片主要化学成分的影响

以茶树2个品种(雁荡毛峰和知仁早茶)为研究材料,采用溶液培养法,研究了铝对茶叶叶片主要化学成分(茶多酚、咖啡碱、氨基酸和维生素C)的影响。结果表明,水培下,10～100mg·L-1质量浓度的铝可显著提高茶多酚的质量分数,与对照相比,50mg·L-1质量浓度下雁荡毛峰茶多酚的质量分数提高了180%,知仁早茶提高了100.6%;10～50mg·L-1质量浓度的铝可提高咖啡碱、氨基酸的质量分数,但100mg·L-1质量浓度下显著降低了咖啡碱和氨基酸的质量分数,雁荡毛峰降低了5.3%、25.8%,知仁早茶降低了2%、7.2%;不同质量浓度的铝对维生素C的质量分数影响不大;低质量浓度的铝处理降低茶树的丙二醛质量分数,而高质量浓度的铝处理(100mg·L-1)提高了丙二醛质量分数。结果证明水培条件下,10～50mg·L-1铝可明显提高茶叶品质,100mg·L-1质量浓度会降低茶叶品质。     

花园城市的生态建设规划—以广州市为例

从城市规划学、生态学、景观生态学及其规划等理论与实践的基础上，研究广州市城市园林绿地景观系统的现状和广州建设成花园城市目前所存在的问题，系统地闻述了广州建设成花园城市所必须遵守的指导原则和指导思想。并针对广州花园城市建设中城市园林绿地系统的规划提出合理化建议。     

A Geochemical Survey of Topsoil in the City of Oslo, Norway

The city of Oslo is situated centrally in the Oslo-graben, which is a Permian rift basin consisting of different kinds of volcanic and sedimentary rocks. In the summer of 1998, approximately 300 samples of surface soil (2–3cm) were taken systematically, 1km^–2. The investigated area covers about 500km². Samples were dissolved in 7M HNO₃ and analysed for 29 elements with ICP-AES, mercury with cold-vapour technique (CV-AAS) and arsenic and cadmium with a graphite furnace (GF-AAS). A factor analysis is frequently used to identify relationships among sets of interrelated variables. To describe the covariant relationships among the elements, a factor analysis has been completed. The first factor contains the elements Sc, Fe, Li, Co, Al, Cr, Be, K, Ni, V, Mg, Y, Ba, Zr, Mn and As (listed with decreasing communality). These elements are typical for the minerals in the area and most of these elements have a near normal distribution. Sources for this factor are probably geological. The second factor contains Cd, Hg, P, Zn, Cu, Ba and Pb. They have a log-normal distribution. Road traffic is probably one of the sources contributing to this factor. In Norway studded tyres are used frequently in the winter season which results in large amounts of road dust. Leaded petrol has been a major source for Pb but is not in use any more. Wear and tear of tyres and brakes contribute also to this factor. Other sources contributing to this factor are probably industry, rubbish incineration, crematoria and release of some of these elements from structural material by fire. Factors 3, 4 and 6 with elements such as Ca, Na, La, Ti and Sr probably have geological sources. They are associated with minerals like amphiboles, pyroxenes and feldspars and some of the elements are from sea aerosols. Factor 5 contains Mn, Cd, Zn, As and Pb. Manganese may be derived from many different sources such as rock weathering, windblown dust, agriculture and traffic. Since As and Mn are placed in both factor 1 and 5 they probably have both geological and anthropogenic sources. Concentrations of the elements in the second factor are much higher in the central parts of Oslo, than in the rest of Oslo. The median value of Hg in the centre is 0.48mgkg^–1, which is 8 times higher than that in the rest of the city. Also, the other elements have much higher levels in the centre. The industrial district north-east of the centre also has high values. The distribution of arsenic is regular throughout the whole city, but has a slightly higher level in the centre. Norm values for contaminated land used by the Norwegian authorities are 2mg As kg^–1 and 25mg Cr kg^–1. Of 297 samples, 61% contain more than 25mg Cr kg^–1 and 79% more than 3mg As kg^–1, which is the detection limit of the analysis. These samples will therefore be regarded as contaminated. Factor analysis places these elements in the geological factor. The Norm value of zinc is 150mgkg^–1, and 40% of the samples contain more than this. The Norm value of lead is 150mgkg^–1, and 35% of the samples contain. Road traffic is probably the major source for these elements.     

西安地区土壤CO2 释放量和释放规律

根据碱溶液吸收法,对西安地区不同植被条件下土壤CO2释放量进行了昼夜观测,观测资料显示,西安地区各月份土壤CO2释放量在一昼夜内具有明显的变化,从当日上午到次日上午,CO2释放量表现出由低变高再变低的规律,土壤CO2释放量变化与温度变化具有相同的特征,但释放量的变化具有滞后性,相对于温度的变化滞后4－6h左右,温度是决定土壤CO2释放量昼夜变化规律的主要因素,它的升高和降低分别造成了土壤CO2和放量的增加和减少,不同植被条件下,土壤CO2释放量不同,林地释放量大于草地,草地释放量大于裸地,夜间12h释放量大于白天12h释放量。