紫甘薯酒发酵工艺条件研究

探讨了紫甘薯酒的主要发酵工艺,采用正交试验法对紫甘薯酒的发酵条件进行了研究。结果表明,发酵液pH和酵母接种量是影响主发酵的主要因素,温度为次要因素;在最优发酵参数发酵液pH 3.8、酵母接种量3%、发酵温度18℃的条件下,可得到澄清透亮、口感较好的紫甘薯酒。     

产菊粉酶芽孢杆菌发酵条件优化

采用液体摇瓶培养方法,探讨了碳源、氮源、pH值、培养温度等各种因素对巨大芽孢杆菌(Bacillus megaterium)分泌菊粉酶能力的影响.通过正交试验对主要影响因素进行优化,结果表明,最适产酶发酵条件为:菊粉30.0g/L、酵母膏7.0g/L、NaCl 5.0g/L、K2HPO4·3H2O 3.0g/L,初始pH 6.0,250mL发酵三角瓶装液量为50mL,30℃,160r/min振荡培养2d,酶活力达到最高,为2.354U/mL,比优化前提高了1.43倍.     

泥水盾构废弃泥浆絮凝脱水机理及影响因素分析

为明确泥水盾构废弃泥浆固液分离性能,提高泥浆固液分离效率,采用化学絮凝的方法对建筑废弃泥浆快速泥水分离性能进行了试验研究,开展了不同种类聚丙烯酰胺(PAM)作用下废弃泥浆絮凝沉降试验、颗粒级配试验及浊度试验研究,考察了药剂种类(APAM、NPAM、CPAM)、分子量及用量对废弃泥浆絮凝沉降特性的影响规律。试验结果表明：APAM和NPAM对废弃泥浆固液分离效果显著,CPAM对废弃泥浆并无明显絮凝作用;对于APAM而言,当其分子量分别为1200万,1600万和1800万时,废浆絮凝效果最佳时的添加量分别为0.35g/L、0.3g/L和0.25g/L;对于NPAM而言,当其分子量分别为1200万,1600万和1800万时,废浆絮凝效果最佳时的添加量分别为0.3g/L、0.3g/L和0.25g/L,且在最佳添加量的情况下,底泥体积、底泥含水率和上清液浊最小,泥浆粒径参数D50最大;APAM与废弃泥浆颗粒之间的作用方式主要是“吸附架桥连接”,NPAM与废弃泥浆颗粒之间的作用方式主要是“电性中和”与“吸附架桥连接”。     

金针菇产漆酶发酵条件的优化

采用液体摇瓶培养方法,探讨了碳源、氮源、pH值、培养时间等各种因素对金针菇分泌漆酶能力的影响,并采用正交试验对主要的影响因素进行了优化.优化培养条件为:pH在5.0-6.0范围内有利于金针菇漆酶的分泌,且以pH5.5为最佳;以葡萄糖为最佳碳源,尿素为最佳氮源,Cu2+浓度为60μmol/L有利于漆酶的分泌.正交试验表明,葡萄糖20g/L、尿素2g/L、250mL容量瓶中装液量50mL、pH5.5,以邻联甲苯胺作底物,经7d培养,金针菇漆酶酶活达最高峰,峰值酶活为328U/mL.     

响应面法优化香蕉秸秆厌氧发酵产沼气工艺

为优化香蕉秸秆厌氧发酵产沼气工艺,实现对香蕉秸秆的资源化利用,该研究首先采用单因素试验考察了起始pH、发酵温度、接种物浓度3个因素对香蕉秸秆厌氧发酵总产气量的影响,在此基础上,通过Box-Behnken试验设计及三因素三水平的响应面分析法,对厌氧发酵工艺进行优化。研究结果表明,根据试验数据建立的二次多项式数学模型具有高度显著性(p 0. 000 1),相关系数R~2=0. 996 1,说明该模型拟合度、精确度高,数据合理。通过上述试验研究,得到的最佳工艺条件为:起始pH为7. 87,发酵温度为39. 45℃,接种物浓度为72. 61%。在此条件下,香蕉秸秆厌氧发酵总产气量的预测值为18 017. 20mL,试验值为17 816. 40mL,二者相对偏差为1. 11%。因此,所得模型能够很好地优化香蕉秸秆厌氧发酵的条件并预测总产气量,可为提高香蕉秸秆厌氧发酵产气量及发酵效率提供一定的参考。     

低渗透油田压裂废水处理技术实验研究

通过低渗透油田压裂废水处理系列实验,研究了降黏预处理-Fe/C微电解-絮凝处理技术,有效地降低了废水的COD,考察H2O2、pH、Fe/C比例、Fe/C加量、Ca(OH)2加量及反应时间等影响因素。结果表明此实验的优化工艺条件为:H2O2加量0.5%、pH为1、Fe/C比例1∶1、Fe/C加量5g/L、Ca(OH)2加量3g/L、反应时间120min。     

水产饲料中浒苔添加量与加工工艺研究

研究了浒苔在水产饲料中的添加量和最适加工工艺。以海洋经济鱼类梭鱼为实验对象，做了两个阶段性实验：第一阶段在饲料中按不同比例添加浒苔研究对梭鱼生长的影响。1组为对照组，添加量为0；2—4组为实验组，浒苔添加量分别为10％、15％、20％。保持各组的营养水平基本一致，实验10d，采取摄食率法作为实验方法，记录实验数据，经Excel分析表明，与对照组相比，实验组的各项生长指标高于对照组，其中第3组最优，增重率提高了14．29％，饵料系数降低了0．6。第二阶段研究不同工艺的浒苔饲料对海洋梭鱼生长性能的影响。以新鲜浒苔为基础工艺组，以浒苔干粉、添加柠檬酸沸煮、冷冻处理浒苔为实验组，即工艺一、工艺二、工艺三。同样以摄食率法作为实验方法，实验期10d，记录实验数据，经Excel分析表明，工艺一和工艺二增重率分别提高了6．37％、7．37％，工艺二饵料系数为2．83。     

气田压裂返排液氧化处理实验研究

以四川某气田压裂返排液为研究对象,采用破胶絮凝处理后进行氧化对比实验,氧化剂选用高锰酸钾、过硫酸钾、次氯酸钠、Fenton试剂。研究表明,絮凝实验最佳条件为氧化钙、硫酸铝和硫酸亚铁投加量分别为3,1,1 g/L。4种氧化方法的最佳实验条件为:高锰酸钾投加量0.5 g/L,pH值为4;过硫酸钾投加量0.25g/L,pH值为6;次氯酸钠投加量15 g/L,pH值为4;Fenton氧化方法pH值为3.5,双氧水投加量25 g/L,七水硫酸亚铁投加量10 g/L。出水COD_(Cr)最多可降至800 mg/L左右,最大COD_(Cr)去除率72.96%,处理效果良好,为后续处理创造了条件。     

不同菌剂处理下猪粪和牛粪堆肥前期性质变化

以猪粪和牛粪为堆肥原料,设计了人工接种MixF-3菌剂堆肥、添加灭活菌剂堆肥和自然堆肥3个处理进行堆肥前期实验,探讨堆肥9d过程中温度、水分、有机碳、全氮和微生物量碳等参数的变化。结果表明,按1L/t接种MixF-3混合菌剂堆肥温度升温快,猪粪堆肥第48h和第84h时温度分别达到66℃和71.5℃,牛粪堆肥第48h时温度达69℃,明显高于灭活菌剂处理组和CK对照组。随着堆肥的进行,各处理组水分含量缓慢下降,牛粪比猪粪含水量略高。人工接种菌剂的猪粪和牛粪堆肥处理组中pH变化幅度小,有机碳碳含量的下降幅度比灭活组和自然堆肥组大,分别下降15.64%和11.25%,全氮含量缓慢升高但变化不大,人工接种牛粪比猪粪处理组中堆肥全氮含量升幅高;在猪粪和牛粪堆肥中人工接种菌剂微生物量碳降幅最小,分别为9537μg/g和3212μg/g,表明在猪粪和牛粪堆肥原料中添加MixF-3复合菌剂有利于微生物繁殖生长,同时拓宽了菌剂使用的单一性,更具有普遍性意义。     

生物质炭与土壤的相互作用对BDE-47吸附行为的影响

本研究将人工制备的生物质炭以0%~2%范围的量添加到受试土壤中,通过比较生物质-土壤体系的理论吸附容量和实际吸附容量,初步阐明生物质炭与土壤的相互作用对BDE-47在土壤中的吸附行为的影响。当生物质炭的添加量为0.1%、0.5%、1.0%时,生物质炭与土壤的相互作用对BDE-47的吸附行为的影响不明显;当生物质炭添加量为2.0%,BDE-47的吸附平衡浓度Ce为0.95μg/L时,生物质炭与土壤的相互作用可以抑制土壤对BDE-47的吸附,使吸附能力降低了33%,而当Ce为9.5μg/L时,生物质炭与土壤的相互作用可以促进土壤对BDE-47的吸附,使吸附能力提高了146%。生物质炭与土壤的相互作用可以影响BDE-47在土壤中的吸附行为,影响程度的大小与生物质炭的添加量和吸附平衡浓度有关。     

AN APPLICATION RUNOFF MODEL STRATEGY FOR UNGAGED WATERSHEDS1

ABSTRACT: Mathematical models for predicting watershed surface flow responses are available, most of which are elaborate nonlinear numerical surface and channel flow models linked with infiltration models. Such models may be used to make predictions for ungaged areas, assuming an acceptable fitting of the model to the topography and roughness of the real system. For some application purposes, these models are impractical because of their complexity and expensive computer solutions. A procedure is developed that uses a complex model of an ungaged area to derive a simpler parametric nonlinear system model for repetitious simulation with input sequences. The predicted flow outputs are obtained with the simpler model at significant savings of money and time. The procedures for constructing a complex kinematic model of a 40 acre (161,880 m²) reference watershed and deriving the simpler system model are outlined. The results of predictions from both models are compared with a selected set of measured events, all having essentially the same initial conditions. Peak discharges ranged from 3 to 118 ft³/sec (0.085 to 3.34 m³/sec), which includes the largest event of record. The inherent limitations of lumped systems models are demonstrated, including the bias caused by their inability to model infiltration losses after rainfall ceases. Computer costs and times for the models were compared. The derived simple model has a cost advantage when repeated use of a model is required. Such an applications hydrologic model has an engineering tradeoff of reduced accuracy, and lumping bias, but is more economical for certain design purposes.     

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.     

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.     

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.     

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.     

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.     

Biodiversity and biotechnology

The maintenance of biodiversity is urged from many quarters and on grounds ranging from aesthetic considerations to its usefulness, particularly for biotechnology. But regardless of the grounds for preserving biodiversity, writers are generally in agreement that it should be preserved. But, in examining the various references biodiversity, such as species diversity, genetic diversity, and habitat diversity, it is apparent that we cannot aim to preserve biodiversityas such, since there are a number of conflicts in any such undertaking. In preserving one aspect of biodiversity, we damage another aspect. Five arguments which attempt to ground our moral concern for biodiversity are reviewed and critiqued, not only for their consistency but also for their power to move us to action. The final section of the paper shows how conflicts in the values of personal and environmental health can impair ethical action and especially policy formation.An earlier version of this paper was read at the conference on Agriculture, Food, and Human Values: Tradition and Change, Orlando, Florida, October 7–9, 1987.