La(Ⅲ)对UV-B辐射胁迫下大豆叶绿素合成与降解影响的机理

采用水培实验方法研究了稀土元素La(Ⅲ)对紫外辐射(UV-B:0.15Wm-2,0.45Wm-2)胁迫下大豆(Glycine max)幼苗的δ-氨基乙酰丙酸(ALA)、胆色素原(PBG)、原叶绿素(酸)(Pchl)、原卟啉IX(Proto-IX)、镁原卟啉(Mg-Proto)等5种叶绿素(Chl)合成中间产物含量及Chl降解关键酶-叶绿素酶(Chlase)活性的影响,从叶绿素的生物合成及降解角度诠释La(Ⅲ)对UV-B辐射胁迫下大豆幼苗叶绿素含量影响的机理。实验结果表明:La(Ⅲ)具有提高叶绿素生物合成中间产物——ALA(δ-氨基乙酰丙酸)、PBG(胆色素原)、Proto-IX(原卟啉IX)、Mg-Proto(镁原卟啉)含量的作用,促进Pchl(原叶绿素)转化为叶绿素,进而缓解UV-B辐射胁迫下中间产物PBG、Proto-IX和Mg-Proto的形成,使叶绿素的生物合成受阻,受阻位点为ALA→PBG。     

Contamination of Forest Soils in the Vicinity of the Sedimentation Pond after Zinc and Lead Ore Flotation (in the Region of Olkusz,Southern Poland)

In the technological processes of ore flotation in the non-ferrous metal industry flotation, tailings constitute up to 98% of the total of the processed material. They are stored in sedimentation ponds as fine-grained drift containing an excess of heavy metals, mainly zinc, cadmium, lead and copper. After the dehydration and drying up of the surface of sedimentation ponds, these metals are carried with dust by the wind and they are accumulated in the vicinity of the ponds in humus horizons of soils causing considerable degradation and even devastation. In this publication, we have presented the results of research on the negative influence of such a structure on the soils of an adjacent fragment of forest and its dependence on the distance from the sedimentation pond. The level of degradation of the soils under research has been assessed on the basis of changes and transformations of the morphological soil profiles, the level of alkalization and accumulation of heavy metals (Zn, Pb, Cd) in the topsoil layers and their translocation in the soil horizons. The following soils have been distinguished in the investigated area: Haplic Podzols distorted and degraded as well as Urbic Anthrosols. The acquired results have served to depict the spatial accumulation of these heavy metals in the topsoil layers. The highest accumulation of heavy metals and the degradation of the forest sites connected with it has occurred in the vicinity of a sedimentation pond drain channel. Soil remediation has been recommended in this area.     

我国土壤污染退化状况及防治对策

土壤污染退化已成为我国乃至全球性土壤退化的主要表现形式之一。本文在分析我国土壤资源污染退化状况和发展态势的基础上,着重分析了土壤污染退化对食物安全和生态环境效应的影响,并探讨了其原因,提出了防治我国土壤资源污染退化的对策。     

长江上游典型地区的土壤退化评价

以长江上游典型区——彭州市为例，在该区SOTER（1：50000）数据库的支持下，建立了基于AHP法的土壤退化评价系统。对样区53个SOTER单元进行了评价，生成了相应的专题评价图。     

土壤频繁应用杀虫剂的降解动力学统一模型

This paper deduces a kinetic model for microbial degradation of pesticides in soils:x=x0(M/[M-m0 m0exp(μt)])^kM/μ where x is the concentration of pestcide at time t,x0 the initial concentration of the pesticide,m0 the initial number of pesticide-degrading microogranisms,M the carrying capacity for the microorganisms,μ the specific growth rate of the microorganisms,and k the rate constant for the pesticide degradation.In periodic applications of pesticides,this model can be used to continumously describe every degradation curve.Whether a lag phase occurs or not,we can obtain the minimum residue of the pesticide(xe): xc=xdexp(-kMτ)/[1-exp(-kMτ)]where τ the regular time intervals between applications ,and xd the dosage of the pesticide.     

土壤侵蚀退化研究

土壤退化是全球性的重大环境问题之一,直接威胁人类的生存。在引起土壤退化的诸因素中,土壤侵蚀是最普遍和最重要的因素。在前人土壤侵蚀退化研究成果的基础上简单回顾了其发展现状,重点综述了土壤侵蚀退化机理,并针对性地提出了土壤侵蚀退化防治措施。     

生态系统健康理论与评价方法探析

阐述了生态系统健康理论的形成与发展以及评价生态系统健康的方法和指标 ,并简介了我国生态系统健康理论在温室生态系统的应用。     

西藏自治区那曲县草地退化的动态变化分析

以1994年和2001年的TM图像作为原始数据，在GIS技术支持下，对西藏自治区那曲县的草地资源利用和草地退化的现状进行了分析，并在此基础上探讨了草地退化强度变化和草地型动态演替的规律。研究结果表明：那曲县草地资源处于低效利用状态，草地退化现象明显；草地退化强度呈现出从无明显、轻度退化向中、重度退化演替的趋势，主要体现为无明显、轻度退化草地面积比重下降，中、重度退化草地面积比重上升；草地型呈现出从高质量型向低质量型演替的趋势，主要体现为藏北嵩草草地型——高山嵩草草地型、高山嵩草草地型——紫花针茅草地型、藏北嵩草草地型——紫花针茅草地型的转移。     

原料连续添加和酸酶循环利用法(CACU法)降解植物纤维素新技术

以乙酸、草酸、盐酸、硫酸等单酸、二酸、三酸混和及纤维素酶降解植物纤维素的正交试验得出的最佳工艺条件为基础,进一步研究出一种原料连续添加和酸酶循环利用法降解植物纤维素新技术(CACU法)。该技术的整个过程只需要12步操作,5或6套设备,包括3～4套反应釜和2套贮罐。在常压、温度100℃、反应15h的条件下,以CH₃COOH,HCl和纤维素酶为反应剂,按照该工艺技术能使纤维素转化成葡萄糖的转化率达95.34%,反应终液中的葡萄糖浓度达3.21%。与常规技术相比,该新技术只需25%的醋酸和50%的盐酸量,可以较大幅度地降低纤维素转化成葡萄糖的成本。因此,该技术具有条件要求低、工艺简单、成本低和周期短等特点,是一种值得进一步开发和推广的技术。     

An investigation of carbohydrate and protein degradation ratios,nitrogen to energy synchronization and hourly effective rumen digestion of barley: effect of variety and growth year

The objective of this study was to investigate rumen available soluble, insoluble and total protein (CP), estimated structural (SC) and non‐structural carbohydrate (starch: ST), degradation characteristic ratios and hourly effective degradation of six barley varieties during three consecutive growth years (2003, 2004, 2005). The magnitude of the differences was determined between the varieties and growth years. Measured degradation kinetics included soluble fraction (S), undegradable fraction (U), lag time (T₀) and rate of degradation (K_d) of the insoluble but degradable fraction (D). Rumen available soluble, insoluble, and total N, SC and ST and the rumen degradation characteristic ratios were determined using the Tamminga rumen degradation ratio system. Characteristics of the hourly effective degradation between N and carbohydrate (CHO) among the six barley varieties for 3 years were also studied. The degradation ratios included were total rumen available N and carbohydrate ratio (FN/FCHO), rumen available soluble N and carbohydrate ratio (SN/SCHO), and rumen available insoluble N and carbohydrate ratio (EN/ECHO). Results show that both the barley variety and growth year had a significant effect on degradation kinetics (S, D, U, T₀ and/or K_d). Differences in the ratio of FN/FCHO among varieties ranged from 16.6 to 19.0 g/kg (p < 0.01). There was no difference in SN/SCHO (p > 0.05) with an average of 4.9 g/kg. The difference in the EN/ECHO ratio tended to be significant among the varieties (p = 0.069) ranging from 18.4 to 21.3 g/kg. Differences in the hourly effective degradation between N and CHO were relatively small at shorter incubation times (2–4 h) However, as the length of rumen incubation increased (12–24 h), much larger differences in the rate of effective hourly degradation were observed. In conclusion, both barley variety and growth year had significant effects on rumen degradation kinetics. The mean FN/FCHO ratio of 17.2 (16.6–19.0) was observed for the six barley varieties in this experiment. All barley varieties exhibited a less optimal rumen fermentation ratio (17.2 < optimum: FN/FCHO = 25 to 33 g N per kg CHO). The large differences in the degradation kinetics, characteristics ratios and hourly effective degradation among barley varieties and growth years may help to explain some of the large variations that are seen in cattle performance.