物联网技术在城市生活垃圾收运系统中的应用

我国的城市生活垃圾收运系统因其回收率低,监管难等问题,一直受到社会的广泛关注,而物联网技术因其可追溯性、动态性等特点,在解决该问题上表现出其显著优势。简要介绍了物联网技术的作用及其应用领域,总结了国内外基于物联网技术的城市生活垃圾收运情况,以我国上海市餐厨垃圾收运情况为案例,对其现状和目前存在的问题进行了总结,并结合物联网技术对餐厨垃圾信息化收运的管理方法进行了展望。     

Adapting food systems of the Indo-Gangetic plains to global environmental change: key information needs to improve policy formulation

The Indo-Gangetic plain (IGP; including regions of Pakistan, India, Nepal, and Bangladesh) is generally characterised by fertile soils, favourable climate and an abundant supply of water. Nevertheless, the challenge of increasing food production in the IGP in line with demand grows ever greater; any perturbation in agriculture will considerably affect the food systems of the region and increase the vulnerability of the resource-poor population. Increasing regional production is already complicated by increasing competition for land resources by non-agricultural sectors and by the deterioration of agri-environments and water resources. Global environmental change (GEC), especially changes in climate mean values and variability, will further complicate the agricultural situation and will therefore, have serious implications for food systems of the region. Strategies to reduce the vulnerability of the region's food systems to GEC need to be based on a combination of technical and policy options, and developed in recognition of the concurrent changes in socioeconomic stresses. Adaptation options need to be assessed with regard to their socioeconomic and environmental efficacy, but a greater understanding of the interactions of food systems with GEC is needed to be able to do this with confidence. This paper discusses information needs relating to resource management and policy support to guide the development of research planning for increasing the robustness of IGP food systems to GEC. Further information is needed to develop a range of adaptation strategies including augmenting production and its sustainability, increasing income from agricultural enterprises, diversification from rice–wheat systems, improving land use and natural resource management, and instigating more flexible policies and institutions.     

重金属对食品的污染及其危害

铅、砷、汞、镉、锡等有毒重金属通过各种途径污染食品,沿食物链进入人体后,给人体健康带来严重危害.本文综述了几种重金属对食品的污染及其来源,对人体的危害及其预防,以便提高人们的食品安全意识,加强环境保护,维护人体健康.     

南京港1995—1998年食品卫生微生物监测结果分析

在分析港口所属职工食堂及附近饭店的食品、餐具卫生状况及特点的基础上，根据港口及附近餐饮单位个人承包多，卫生经费投入少，食品卫生淡化的现状，对改善卫生状况提出意见和建议。     

菜市场噪声对周围环境的影响

南方的菜场都有从凌晨开始即进行贸易的特点，以盐城市众多菜场中最具代表性的老虎桥露天菜场为例，对菜场噪声及其对环境的影响进行了监测与评价，并提出控制措施。     

生态小区建设中食物垃圾处理技术

分析了食物垃圾的产量、特点。综述食物垃圾的常用处理方法,提出了生态小区建设中食物垃圾的合理解决方法．将食物垃圾的处理与生活污水的处理就近有机结合,为生态小区建设中废物资源化处理和利用提供有效的依据。     

草海典型高原湿地食物链中汞同位素组成特征

以国家自然保护区贵州草海高原湿地为研究对象,系统采集了不同种群水生生物,通过测定各样品总汞、甲基汞含量、碳氮同位素和汞同位素组成,以探究汞在食物链营养级传递过程中的同位素分馏特征.结果显示,所有样品均发生了汞同位素质量分馏(MDF)和非质量分馏(MIF),且均表现出偏负的δ202Hg (-0.93‰±1.32‰,n=14)以及偏正的Δ199Hg(0.79‰±0.76‰,n=14).除穗状狐尾藻(δ15N=-1.88‰)以外,δ15N和δ202Hg之间存在显著的正相关关系(r=0.58,P0.05),表明汞在食物链的生物富集过程中相对富集偏重的汞同位素.Δ199Hg和δ15N之间也表现出显著正相关性(r=0.67,P0.05),同时Δ199Hg与生物中甲基汞比例(%MeHg)之间存在显著正相关性(r=0.58,P0.05),表明汞的非质量分馏程度随食物链的升高而变大,可能是由于营养传递的过程中生物体内甲基汞的比例升高所致.     

有机食品的发展现状及趋势探讨

介绍了有机食品的概念,分析了国际有机食品运动的发展方向、推动因素和市场潜力,预测今后几年内全球有机产品市场的年平均发展速率为15％－20％。同时,还分析了我国发展有机食品的国际环境、农业基础和发展模式,认为发展有机农业和有机食品是跨越绿色贸易壁垒的良策,国内的消费市场潜力和空间巨大,预测到2010年,我国有机食品占国内食品市场的比例可望达到1.0%-1.5%,占全球有机食品市场的份额则可望达到3.0%。     

An inverse model for the analysis of the Venice lagoon food web

A steady-state model of the Venice lagoon food web was constructed, based on a comprehensive set of data, which were collected in the years 2001-2005. Energy flows were estimated by means of an inverse methodology of constrained optimization based on the Minimum Norm criterion, i.e. on the minimization of both the sum of squares of the residuals and of the sum of squares of energy flows. The solution was constrained by a set inequalities, which were derived from general eco-physiological knowledge and site specific data on energy flows. The trophic network was represented by thirty-two nodes, including single-species compartments for the species of high economical or ecological relevance. Mass balance equations were weighted, in order to obtain meaningful results in presence of large differences, up to 5 orders of magnitude, among biomasses. A perturbation technique was applied, with the purpose of reducing the risk of finding solutions heavily affected by the set of constraints and of obtaining a more robust representation of the energy flows. The main patterns of energy flow are consistent with those obtained in previous attempts at modelling the Venice lagoon food web. Micro- and macro-phytobenthos account for the largest fraction of the primary production. Energy is then transferred towards higher trophic levels by means of two main pathways: the recycling of dead biomass through the detritus compartment and the direct consumption by grazers. The first pathway is the most important and accounts for approximately two/thirds of the energy transferred to the second trophic level.     

Relationship between filtration activity and food availability in the Mediterranean mussel <Emphasis Type="Italic">Mytilus galloprovincialis</Emphasis>

The filtration activity of the Mediterranean mussel, Mytilus galloprovincialis, was assessed under different concentrations and compositions of seston by using a new automated image acquisition and analysis system. This approach allowed for frequent and simultaneous measurements of valve gape and exhalant siphon area. Filtration rates were measured through clearance measurements whereas pumping rates were measured using hot-film probes. The average filtration rate (17.5 l g h⁻¹ DW⁻¹ for a 0.36 g DW mussel) recorded during the present study was higher than those available for Mytilus edulis when standardized to flesh dry weight but almost equivalent (17.5 l h⁻¹ g DW⁻¹ for a 53 mm shell length mussel) to those rates when standardized to shell length. Immediately after the addition of algal cells (Isochrysis galbana; 4.5 μm in size), valve gape, exhalant siphon area and filtration rate increased quickly as mussels reached their maximum filtration activity. These three parameters then gradually decreased until complete closure of the shell. The algal cell concentration inducing this transition was close to 800 cells ml⁻¹ and 0.5 μg Chl a l⁻¹. When algal concentration was maintained above this threshold by successive algal additions, both valve gape and exhalant siphon area remained maximal. Temporal changes in the exhalant siphon area were continuous as opposed to those of valve gape. Therefore, despite the significant correlation between these two parameters, valves and siphon were sometimes dissociated due to a reduction of the area or even a closure of the exhalant siphon while the valves remained open. The velocity of exhaled water tended to be constant irrespective of exhalant siphon area and thus pumping rates were a linear function of exhalant siphon area. Consequently, reductions in exhalant siphon area and pumping rate were almost similar in M. galloprovincialis. Our results thus clearly support the hypothesis that exhalant siphon area constitutes a better proxy of pumping rate than valve gape as already suggested for Mytilus edulis. Finally, the high filtration rates measured during the present study together with the high concentrations of inorganic matter (> 40 mg DW l⁻¹) requested to alter those rates suggest that the studied mussels were well adapted to oligotrophic waters featuring strong hydrodynamism and frequent sediment resuspension events.