工科有机化学教学目标与教学改革的探索

工科有机化学是面向工科专业开设的一门基础课,以往的教学只是按章节顺序详细介绍各类反应,内容多,难以记忆,而且各专业间差别不大.随着教改的不断发展,规定的教学时数愈来愈少,如何解决内容多与时间少的矛盾,如何体现专业特点成为我们急待解决的问题.我们主要从教学目标、教学内容、教学手段方面进行了一些尝试,取得了较好的效果.     

Chemical leasing: cooperative business models for sustainable chemicals management. Summary of research projects commissioned by the Austrian Federal Ministry of Agriculture, Forestry, Environment and Water Management

- Sustainable chemistry - Section editors: Klaus Günter Steinhäuser, Steffi Richter, Petra Greiner, Jutta Penning, Michael AngrickBackground, Aim and Scope Chemicals play a vital role in the day-to-day life of industrialised societies. Their use is not restricted to the chemical enterprises per se, but is a crucial part of production processes in a lot of industrial sectors. Traditional instruments of environmental policy (such as bans, restrictions) can only deal with the most hazardous substances. The Johannesburg Implementation Plan of 2002 calls for more sustainable patterns of production and consumption, and sets the year of 2020 as a goal to use chemicals in a way that human health and the environment are not endangered. Political instruments should not only gather more knowledge about the properties of chemicals, but should also stimulate the environmentally sound use of chemicals. Existing business models should therefore be reviewed in relation to this strategic approach to encourage marketing options with respect to the environmental focus.Main Features Business models were examined for their effects on the consumption of chemicals and amount of waste emissions in relation to their economic potential. Different possibilities for cooperation of supplier, user and disposal companies were elaborated and examined with a view to the specific situation in Austria.Results and Discussion A range of cooperative models – summarised under the term ‘chemical leasing’ - was identified, which can contribute to a more efficient use of resources. 12 main possible application areas (cleaning, lubrication, paint stripping and others) have been identified in Austria. If chemical leasing models were applied in these areas, the amounts of chemicals currently used could be reduced by one third (53,000 tonnes per year). Cost reductions of up to 15 % can be expected.Conclusion The application of chemical leasing models can contribute considerably to achieving more sustainable and resource-efficient patterns of production. The Austrian Ministry for Environment has therefore decided to subsidise the further practical implementation of these new service-oriented business models. Pilot projects in 4 enterprises, which are supervised by consulting companies, are currently being carried out. Recommendation and Outlook The experiences of the pilot projects will serve as valuable building blocks for the wider use of chemical leasing models. Furthermore, the UNIDO Cleaner Production Centres have expressed their clear interest and will examine the possibility to use chemical leasing as a part of their Cleaner Production Programmes.     

Adaptive Management, Monitoring, and the Ecological Sustainability of a Thermal-Polluted Water Ecosystem: A Case in Sw Spain

The construction of the Almaraz nuclear power plant in Spain in the 1970s posed interesting environmental problems concerning the construction of a cooling reservoir (Arrocampo reservoir) to cool the steam condensers and the consequent heating of the reservoirs water. The socio-political context forced decision makers to set up a project for the monitoring and management of the environmental impacts derived from the construction and operation of the power plant. Numerous scientific and technical specialists collaborated with the representatives of social groups towards two goals: the improvement of the biodiversity and of the efficiency of the cooling system. These goals involved the monitoring and managing of the system with respect to different biological aspects, mainly limnology, ichthyology, avian fauna and vegetation. The management plan yielded numerous results. The control of the water eutrophy is one of the most important due to its repercussion on the rest of the ecosystem, especially the fish fauna. The development of the shore vegetation slowly increased the patchwork nature of the reservoir, leading to a greater diversity of the avian species. This paper describes the monitoring and management of the Arrocampo ecosystem, the condition before and after the construction of the reservoir and the results obtained concerning some biological communities.     

化学活化法制备麻疯树果壳活性炭的实验研究

以麻疯树果壳为原料，KOH为活化剂，通过化学活化法制备活性炭。考察了反应温度、反应时间和碱炭比（KOH与麻疯树果壳炭化料的质量比）等因素对活化结果的影响，并利用N2吸附和BET等现代分析测试方法来表征活性炭的结构特征。结果表明，化学活化法制备的活性炭吸附剂性能较好，且当活化温度为850℃，活化时间为240min，碱炭比R=4时制得活性炭产品的质量最好；化学活化法制备的活性炭为微孔吸附剂，在最佳条件下得到最大的碘吸附值和比表面积分别为2218．44mg／g和1890m^2／g。     

A Comparison of Protocols and Observer Precision for Measuring Physical Stream Attributes1

Abstract: Stream monitoring programs commonly measure physical attributes to assess the effect of land management on stream habitat. Variability associated with the measurement of these attributes has been linked to a number of factors, but few studies have evaluated variability due to differences in protocols. We compared six protocols, five used by the U.S. Department of Agriculture Forest Service and one by the U.S. Environmental Protection Agency, on six streams in Oregon and Idaho to determine whether differences in protocol affect values for 10 physical stream attributes. Results from Oregon and Idaho were combined for groups participating in both states, with significant differences in attribute means for 9 out of the 10 stream attributes. Significant differences occurred in 5 of 10 in Idaho, and 10 of 10 in Oregon. Coefficients of variation, signal‐to‐noise ratio, and root mean square error were used to evaluate measurement precision. There were differences among protocols for all attributes when states were analyzed separately and as a combined dataset. Measurement differences were influenced by choice of instruments, measurement method, measurement location, attribute definitions, and training approach. Comparison of data gathered by observers using different protocols will be difficult unless a core set of protocols for commonly measured stream attributes can be standardized among monitoring programs.     

Monitoring Long-term Trends in Sulfate and Ammonium in US Precipitation: Results from the National Atmospheric Deposition Program/National Trends Network

Data from the National Atmospheric Deposition Program/National Trends Network (NADP/NTN) indicate significant changes have occurred in precipitation chemistry and the chemical climate in the United States (US). A Seasonal Kendall Trend (SKT) analysis shows statistically significant increases in precipitation ammonium concentrations at 64% of 159 continental US NADP/NTN sites evaluated from Winter 1985 to Fall 2004 (Dec. 1984 – Nov. 2004). Sulfate decreases were widespread, with an SKT analysis indicating statistically significant decreases at 89% of sites evaluated. Ratios of chemical equivalent concentrations of ammonium to sulfate in precipitation have risen to the extent that ammonium now exceeds sulfate over more than half of the continental U.S. on a precipitation-weighted-mean annual basis. These trends in the concentrations of ammonium, sulfate, and other species have been accompanied by significant decreases in the frequency of acidic precipitation (pH < 5.0) in the last decade.     

成都市干性降落物与道路粉尘的化学组成对比研究

为了弄清大气中微粒子的化学组成的特征，我们自2001年12月在成都市采集了干性降落物和道路粉尘，并对其水溶性阴离子成分进行了比较。通过分析认为干性降落物对道路粉尘的化学组分有影响。同时道路混凝土的污染物亦可进入道路粉尘。     

USING INFILTRATION ENHANCEMENT AND SOIL WATER MANAGEMENT TO REDUCE DIAZINON IN RUNOFF1

ABSTRACT: Pesticide runoff from dormant sprayed orchards is a major water quality problem in California's Central Valley. During the past several years, diazinon levels in the Sacramento and San Joaquin Rivers have exceeded water quality criteria for aquatic organisms. Orchard water management, via post‐application irrigation, and infiltration enhancement, through the use of a vegetative ground cover, are management practices that are believed to reduce pesticide loading to surface waters. Field experiments were conducted in Davis, California, to measure the effectiveness of these management practices in reducing the toxicity of storm water runoff. Treatments using a vegetative ground cover significantly reduced peak concentrations and cumulative pesticide mass in runoff for first flush experiments compared with bare soil treatments. Post‐application irrigation was found to be an effective means of reducing peak concentrations and cumulative mass in runoff from bare soil treatments, but showed no significant effect on vegetated treatments.     

WATER QUALITY IMPACTS AND INDICATORS OF METABOLIC ACTIVITY OF THE ZEBRA MUSSEL INVASION OF THE SENECA RIVER1

ABSTRACT: The conspicuous shifts in summertime values of common measures of water qualify that have persisted for 10 years (1993 to 2002) in the Seneca River, New York, as a result of the zebra mussel invasion are documented. Resolution of patterns in time and space is supported by water quality monitoring that extends back to the late 1970s. Patterns are evaluated to describe the stability of impacts and quantify metabolic activity of the invader. The water quality impacts that have persisted unabated for 10 years since the invasion are the most severe documented for a river in North America. Changes in summer median conditions since the invasion include: (1) a 16‐fold decrease in chlorophyll concentration (Chi), (2) a 2.5‐fold increase in Secchi disc transparency, (3) a 17‐fold increase in soluble reactive phosphorus concentration, (4) a 3.7‐fold increase in total ammonia concentration, (5) a greater than 25 percent decrease in dissolved oxygen (DO) concentration, and (6) a decrease in pH of 0.55 units. The strength of these signatures has been driven by anthropogenic influences that include upstream nutrient loading and morphometric modifications of the river, and the functioning of Cross Lake, through which the river flows. This hypereutrophic lake sustains dense zebra mussel populations and related water quality impacts in the river downstream of the lake outflow by acting as a source of veligers and suitable food for this bivalve. Evidence is presented that levels of metabolic activity of the zebra mussel in this river have been resource limited, manifested through increased consumption of Chl and DO with increased delivery of these constituents in the lake's outflow.     

FOREST‐RIVER INTERACTIONS: INFLUENCE ON HYPORHEIC DISSOLVED ORGANIC CARBON CONCENTRATIONS IN A FLOODPLAIN TERRACE1

ABSTRACT: In large floodplain rivers, hyporheic (subsurface) flow‐paths transfer nutrients from productive riparian terraces to oligotrophic off‐channel habitats. Because dissolved organic carbon (DOC) fuels microbial processes and hyporheic microorganisms represent the first stage of retention and transformation of these nutrients, understanding DOC flux can provide information on the constraints of microbial metabolism in the hyporheic zone of rivers. We monitored hydrology, physicochemical indicators, and dissolved organic carbon (DOC) dynamics during low and high discharge periods in the hyporheic zone of a riparian terrace on the Queets River, Washington, to understand what processes control the supply of carbon to subsurface microbial communities. As discharge increased, terrace hyporheic flowpaths changed from parallel to focused, and the location of surface water inputs to the terrace shifted from the terrace edge to head. Overall, DOC concentrations decreased along hyporheic flowpaths; however, concentrations at points along the flowpaths varied with position along the head gradient and age of the overlying vegetation. We estimated that there is insufficient DOC in adverting surface water to support hyporheic microbial metabolism in this riparian terrace. These trends indicate that there are additional carbon sources to the subsurface water, and we conclude that DOC is leaching from overlying riparian soils within the forest patches. Thus, subsurface DOC concentrations reflect a balance between surface water inputs, metabolic uptake, and allochthonous inputs from forest soils.