分子氧氧化环己烯反应机理探讨

以分子氧为氧源,金属配合物催化氧化环己烯.反应过程以自由基反应机理为主,在环己烯分子的C=C键和烯丙基碳原子上进行反应,主要产物为2-环己烯-1-过氧化氢(Ⅰ)、2-环己烯-1-酮(Ⅱ)、2-环己烯-1-醇(Ⅲ)和环己烯环氧化物(Ⅳ).当反应时间延长,可引发Ⅱ和Ⅲ型产物及2-环己烯-1-氧自由基β键断裂的分解反应,生成一系列链状产物.探讨了分子氧氧化环己烯反应的机理,并对该研究领域的前景进行了展望.     

铁(Ⅱ)—5—Br—PADAP—吐温—80显色体系的研究及其应用

本文研究Fe(Ⅱ)—5—Br—PADAP—吐温—80新的显色体系的化学反应。用吐温—80作用于Fe(Ⅱ)—5—Br—PADAP体系,在PH5～6范围内,形成穗定的Fe(Ⅱ)—5—Br—PADAP—吐温—80显色体系,产生强烈的增溶增敏作用。配合物的组成比及稳定常数分别为Fe:5—Br—PADAP=1:2,K=3.8×10~(11),显色体系形成后稳定4小时以上,其最大吸收波长(λmax)568nm。表观摩尔吸光系数∑_(568)=9.3×10~4·1mol~(-1)·CM~(-1),在0～20μgFe(Ⅱ)/50ml,服从比耳定律。显色体系形成后加入EDTA、酒石酸和硫脲,其它金属离子形成的配合物被破坏,而Fe(Ⅱ)的配合物相当稳定不被破坏,达到掩蔽干扰离子的作用。用于测定水和工业废水中的微量铁,获得满意的结果。     

一维银配位聚合物光催化降解亚甲基蓝

在搅拌回流条件下,合成了配位聚合物[Ag_4(L)_2(1,4-ndc)_2]_n(L=1,3-双(苯并咪唑-1-亚甲基)苯,1,4-H_2ndc=1,4-萘二羧酸)。对其进行X-射线单晶衍射分析、元素分析和红外光谱分析,配合物具有一维管状链结构。对合成的配合物进行降解亚甲基蓝实验,结果表明该配合物对10 mg/L亚甲基蓝溶液的光催化降解效率高达85.7%。     

稀土水杨醛Salphen希夫碱配合物的合成与表征

利用N,N’-双（水杨醛）缩邻苯二胺配体（L）与稀土金属离子合成了稀土水杨醛Salphen希夫碱配合物{[M（NO3）2]·2H2O;M=La,Nd,Sm},并利用红外光谱（IR）、紫外-可见光谱（UV）、元素分析、摩尔电导率和差热热重（TG—DTA）对配合物的结构做了表征。结果表明,配合物中稀土金属离子M（Ⅲ）的配位数为6,同时还有2个NO3-和配位中心配位。     

红外光度法测定石油类和动植物油常见问题探讨

根据石油类在波数为2930cm-1、2960 cm-1、3030 cm-1全部或部分谱带处有物征吸收的原理,采用红外光度测油仪和水样絮凝富集技术测定石油类、动植物油。     

三峡水域中痕量汞的分光光度法测定

聚乙烯醇(PVA)存在下[HgI4]2-与罗丹明B(RHB)形成配合物[HgI4]2--RHB-PVA,在波长610nm处有最大吸收,表观摩尔吸光系数ε = 6.02×105 L/( mol·cm).结合巯基棉(SCF)对汞的选择性吸附,实现了水样中痕量汞的分离、富集与测定.标准样品富集前后测定的相对标准偏差RSD分别为4.25%和7.40%(n=6).本法应用于三峡水域长江和嘉陵江江段中总汞的测定,回收率为90.6%～111.4%,最低检出浓度0.040μg/L,对比国控点原子荧光光谱分析法监测汞数据,结果令人满意.     

2001年颁布的环境保护行业标准

序号名　　　　　　　　称　　　编　　号发布时间实施时间1辐射环境监测技术规范ＨＪ/Ｔ61 - 2 0 0 1 2 0 0 1 - 0 5- 2 82 0 0 1 - 0 8- 0 12饮食业油烟净化设备技术要求及检测技术规范ＨＪ/Ｔ62 - 2 0 0 1 2 0 0 1 - 0 6 - 0 6 2 0 0 1 - 0 8- 0 13大气固定污染源镍的测定火焰原子吸收分光光度法ＨＪ/Ｔ63 1 - 2 0 0 1 2 0 0 1 - 0 7- 2 72 0 0 1 - 1 1 - 0 14大气固定污染源镍的测定石墨炉原子吸收分光光度法ＨＪ/Ｔ63 2 - 2 0 0 1 2 0 0 1 - 0 7- 2 72 0 0 1 - 1 1 - 0 15大气固定污染源镍的测定丁二酮肟 -正丁醇萃取分光光度法ＨＪ/Ｔ…     

超高效液相色谱法同时测定桦褐孔菌中三种主要化合物的含量

建立超高效液相色谱法(UPLC),测定桦褐孔菌中三种主要化合物原儿茶醛、丁香酸和(E)-4-(3,4-二羟基苯基)丁-3-烯-2-酮含量。采用UPLC法,色谱柱为CORTECS UPLC T3(2. 1mm×100mm,1. 6μm),流动相为乙腈—水(含0. 1%甲酸),柱温为40℃,流速为0. 4mL/min,进样量为1μL,检测波长为280nm。结果表明:原儿茶醛、丁香酸和(E)-4-(3,4-二羟基苯基)丁-3-烯-2-酮分别在0. 1953125—6. 25μg/m L(R2=1. 0000)、0. 1953125—6. 25μg/m L (R2=0.9998)、0. 1953125—6. 25μg/m L(R2=1. 0000)范围内线性关系良好,平均回收率(n=9)分别为98. 150%(RSD=1. 924%)、95. 787%(RSD=2. 487%)、100. 324%(RSD=1. 541%)。不同产地间的桦褐孔菌含量测定结果表明,三种化合物含量的差异较大,吉林长白山最高,俄罗斯西伯利亚次之,黑龙江大兴安岭最低。该方法操作简便、结果准确可靠、重现性好,可为桦褐孔菌的定量分析和质量评价提供科学的依据。     

酸雨及大气颗粒物中可溶性SO_4~(2-)的流动注射—比浊法测定

本文研究了在一定酸度下,以BaCl_2为沉淀剂,OP(聚乙二醇辛基苯基醚)为保护剂的比浊法测定酸雨及大气颗粒物中SO_4~(2-)含量的分析条件,选择的最佳体系为:BaCl_2·2H_2O(2％)—OP(5％)。SO_4~(2-)含量在0.6—7.2μg1ml范围内呈线性关系,回收率为95～105％,相对平均标准偏差小于2.6％。在此基础上与流动注射仪联用,提高了分析速度,改善了精密度。     

国家环境保护总局文件环发[2001]110号关于发布《大气固定污染源镍的测定火焰原子吸收分光光度法》等十一项环境保护行业标准的公告

为贯彻《中华人民共和国环境保护法》,防治环境污染,保护和改善生活环境和生态环境,保障人体健康,加强环境管理,现批准《大气固定污染源镍的测定火焰原子吸收分光光度法》等十一项标准为环境保护行业标准。标准编号、名称如下：1.HJ/T63.1－2001 大气固定污染源镍的测定火焰原子吸收分光光度法2.HJ/T63.2－2001 大气固定污染源镍的测定石墨炉原子吸收分光光度法3.HJ/T63.3－2001 大气固定污染源镍的测定丁二酮肟－正丁醇萃取分光光度法4.HJ/T64.1－2001 大气固定污染源镉的测定火焰原子吸收分光光度法5.HJ/T64.2－2001 大气固定…     

Conversion of temperate forests into heaths: Role of ecosystem disturbance and ericaceous plants

Fire and logging in nutrient-poor temperate forests with certain ericaceous understory plants may convert the forests into heaths. The process of disturbance-induced heath formation is documented by using examples ofCalluna in western Europe,Kalmia in Newfoundland, andGaultheria (salal) in coastal British Columbia. In a cool, temperate climate, rapid vegetative growth ofCalluna, Kalmia, and salal following disturbance results in increasing organic accumulation (paludification), nutrient sequestration, soil acidification, and allelochemicals. These are thought to be the main reasons to conifer regeneration failure in disturbed habitats. If continuation in forest is a land-use objective, then temperate forests with an ericaceous understory should not be logged unless effective silvicultural methods are devised to control the ericaceous plants and restore forest regeneration. Preharvest vegetation control may be considered as an option. Failure to control the understory plants may lead to a long-term vegetation shift, from forest to heathland, particularly in nutrient-poor sites. Successful methods of controllingKalmia andGaultheria, however, have yet to be developed. While theKalmia- andGaultheria- dominated heathlands are undesirable in Canada and the Pacific Northwest, a wide range ofCalluna heathlands of western Europe are being conserved as natural and seminatural vegetation.     

Using Paleo Reconstructions to Improve Streamflow Forecast Lead Time in the Western United States

In water stressed regions, water managers are exploring new horizons that would help in long‐range streamflow forecasts. Oceanic‐atmospheric oscillations have been shown to influence streamflow variability. In this study, long‐lead time streamflow forecasts are made using a multiclass kernel‐based data‐driven support vector machine (SVM) model. The extended streamflow records based on tree ring reconstructions were used to provide a longer time series data. Reconstructed data were used from 1658 to 1952 and the instrumental record was used from 1953 to 2007. Reconstructions for oceanic‐atmospheric oscillations included the El Niño‐Southern Oscillation, Pacific Decadal Oscillation, Atlantic Multidecadal Oscillation, and North Atlantic Oscillation. Streamflow forecasts using all four oscillations were made with one‐year to five‐year lead times for 21 gages in the western United States. This is the first study that uses both instrumental and reconstructed data of oscillations in SVM model to improve streamflow forecast lead time. SVM model was able to provide “satisfactory” to “very good” forecasts with one‐ to five‐year lead time for the selected gages. The use of all the oscillation indices helped in achieving better predictability compared to using individual oscillations. The SVM modeling results are better when compared with multiple linear regression model forecasts. The findings are statistical in nature and are expected to be useful for long‐term water resources planning and management.     

Urban ecological systems: scientific foundations and a decade of progress

Urban ecological studies, including focus on cities, suburbs, and exurbs, while having deep roots in the early to mid 20th century, have burgeoned in the last several decades. We use the state factor approach to highlight the role of important aspects of climate, substrate, organisms, relief, and time in differentiating urban from non-urban areas, and for determining heterogeneity within spatially extensive metropolitan areas. In addition to reviewing key findings relevant to each state factor, we note the emergence of tentative "urban syndromes" concerning soils, streams, wildlife and plants, and homogenization of certain ecosystem functions, such as soil organic carbon dynamics. We note the utility of the ecosystem approach, the human ecosystem framework, and watersheds as integrative tools to tie information about multiple state factors together. The organismal component of urban complexes includes the social organization of the human population, and we review key modes by which human populations within urban areas are differentiated, and how such differentiation affects environmentally relevant actions. Emerging syntheses in land change science and ecological urban design are also summarized. The multifaceted frameworks and the growing urban knowledge base do however identify some pressing research needs.     

Neighbourhood characteristics and urban gardens in the Toledo metropolitan area: staffing and voluntarism,food production,infrastructure, and sustainability practices

Urban gardens are important sources of sustenance for communities with limited access to food. Hence, this study focuses on food production in gardens in the Toledo metropolitan area in Northwest Ohio. We administered surveys to 150 garden managers from November 2014 to February 2015 in our attempt to better understand how neighbourhood racial composition and poverty levels are related to staffing and voluntarism, food production and distribution, the development of infrastructure, and the adoption of sustainability practices in urban gardens. The results from 30 gardens are presented in this paper. We used Geographic Information Systems to map the gardens and overlay the map with 2010 census data so that we could conduct demographic analyses of the neighbourhoods in which the gardens were located. Though the gardens were small – two acres or less – up to 46 varieties of food were grown in a single garden. Gardens also operated on small budgets. Food from the gardens was gifted or shared with friends, family, and neighbourhood residents. Gardens in predominantly minority neighbourhoods tended to have fewer institutional partners, less garden infrastructure, and had adopted fewer sustainable practices than gardens in predominantly White neighbourhoods. Nonetheless, residents of predominantly minority and high-poverty neighbourhoods participated in garden activities and influenced garden operations. Volunteering and staffing were racialised and gendered.     

Predicting deer-vehicle collisions in an urban area

Collisions with deer and other large animals are increasing, and the resulting economic costs and risks to public safety have made mitigation measures a priority for both city and wildlife managers. We created landscape models to describe and predict deer-vehicle collision (DVCs) within the City of Edmonton, Alberta. Models based on roadside characteristics revealed that DVCs occurred frequently where roadside vegetation was both denser and more diverse, and that DVCs were more likely to occur when the groomed width of roadside right-of-ways was smaller. No DVCs occurred where the width of the vegetation-free or manicured roadside buffer was greater than 40 m. Landscape-based models showed that DVCs were more likely in more heterogeneous landscapes where road densities were lower and speed limits were higher, and where non-forested vegetation such as farmland was in closer proximity to larger tracts of forest. These models can help wildlife and transportation managers to identify locations of high collision frequency for mitigation. Modifying certain landscape and roadside habitats can be an effective way to reduce deer-vehicle collisions.     

BIOLOGICAL INDICATORS AND BIOLOGICAL EFFECTS OF ESTUARINE/COASTAL POLLUTION1

ABSTRACT: Sustained interest in and concern about the health status of the aquatic environment has resulted in extensive research focused on (1) effects of pollution on survival, growth, and reproduction of resource species at all life stages; (2) diseases of fish and shellfish, as they may be related to pollution and as they may serve as indicators of environmental stress; and (3) contaminant body burdens in fish and shellfish - their effects on the aquatic animals and their potential effects on humans. Effects, lethal and sublethal, of pollutants on life history stages of fish and shellfish have been documented, as have impacts on local stocks in badly degraded habitats, but as yet there has been no adequate quantitative demonstration of effects on entire aquatic species - probably because of the difficulty in sorting out relative effects of the many environmental factors that influence abundance. Sublethal effects, especially those that result in disease, have been examined intensively, and some diseases and disease syndromes have been associated statistically with pollution. Other pollution indicators (biochemical, physiological, genetic, behavioral, and ecological) have also received some attention, as have body burdens of contaminants in aquatic species. Research, especially that conducted during the past decade, has done much to clarify the many pathways and toxic effects of contaminants on aquatic animals, and has also helped to identify mechanisms for survival of fish and shellfish in the presence of environmental changes caused by human activities.     

Journalists' views of advertiser pressures on agricultural news

All major journalism ethical codes explicitly state that journalists should protect editorial copy from undue influence by outside sources. However, much of the previous research on agricultural information has concentrated on what information various media communicate (gatekeeping studies) or communication's role in increasing innovation adoption (diffusion studies). Few studies have concentrated specifically on organizational and structural constraints that might adversely affect agricultural journalists' ethical standards; those that have, focus largely on farm magazines. A study of newspaper reporters who cover agricultural news found that the most pressing ethical concern is the effect of advertiser (agri-business) pressure on editorial copy, and that their concerns in general parallel those of farm magazine writers and editors. The majority reported being in situations in which they might be exposed to advertiser pressure, including pressures to change or withhold editorial copy. Large minorities suggested that advertising pressures affect the overall environment in which agricultural journalists work, and more than one in ten said they allow advertiser pressures to influence editorial decisions. The newspaper reporters who cover agricultural beats showed slightly more resistance to advertiser pressure than did farm magazine editors in a parallel study.     

Definition Procedures Have Little Effect on Performance of Environmental Classifications of Streams and Rivers

Mapped environmental classifications are defined using various procedures, but there has been little evaluation of the differences in their ability to discriminate variation in independent ecological characteristics. We tested the performance of environmental classifications of the streams and rivers of France that had been defined from the same environmental data using geographic regionalization and numerical classification of individual river valley segments. Test data comprised invertebrate assemblages, water chemistry, and hydrological indexes obtained from sites throughout France. Classification performance was measured by analysis of similarity (ANOSIM). Geometric regions defined by a regular grid and without regard to environmental variables and a posteriori classifications based on clustering the test datasets defined lower and upper bounds of performance for a given number of classes. Differences in classification performances were generally small. The ANOSIM statistics for the a posteriori classifications were around twice that of all environmental classifications, including geometrically defined regions. The hydro-ecoregions performed slightly better for the invertebrate data and the network classification performed slightly better for the chemistry and hydrological data. Our results indicate that environmental classifications that are defined using different procedures can be comparable in terms of their ability to discriminate variation of ecological characteristics and that alleged differences in performance arising from different classification procedures can be small relative to unexplained variation. We conclude that definition procedures might have little effect on the performance of large-scale environmental classifications and decisions over which procedures to use should be based primarily on pragmatic considerations.     

MANGANESE CYCLE IN IMPOUNDMENT WATER

Manganese entering impounded water will undergo a cyclic transformation. Oxidation precipitates manganese from top waters. At the bottom of the lake, biological activity will render manganese soluble by both intracellular as well as extracellular activity. The study was made to demonstrate that biological reduction and transformation, organometallic complexation, together with the presence of carbon dioxide and the lowering of pH all have some effect on the solubility of manganese. Dissolved manganese may be brought back to top waters during the lake overturn and therefore deteriorates the water quality.     

Provincial development plans in Zimbabwe: an analysis of their content,structure and methodology

Zimbabwean provincial plans were instituted to help in the achievement of the national goal of the creation of an egalitarian, socialist and integrated society. The national goal itself was adopted as an antithesis to the dualist society characterised by spatial, economic, social, politican and technological inequalities that Zimbabwe inherited from colonialism. This meant that provincial plans had to play both a functional (or growth allocating/distribution) and a territorial (or redistribution) role.

This paper reviews their role in achieving the national goal by examining their functions, content, structure and methodology. The paper concludes that because of their nature, provincial plans are not suitable tools for the achievement of the national goal.