农业排水沟渠硝态氮吸收动力学特征及相关性分析

为揭示农业排水沟渠NO_3~--N吸收动态变化特征,选择溴化钠(Na Br)为保守示踪剂、硝酸钾(KNO3)为添加营养盐,于2016年10月至2017年4月在合肥地区某一源头溪流开展5次示踪试验,并以TASCC方法和Michaelis-Menten(M-M)方程模拟NO_3~--N吸收动力学特征,结果表明,背景浓度条件下排水沟渠完全混合子渠段U_(amb)和V_(f-amb)的变化范围分别为11.40~69.13μg·(m~2·s)~(-1)[均值为34.45μg·(m~2·s)-1]、0.07~0.43 mm·s~(-1)(均值为0.24 mm·s~(-1)),相应地Sw-amb变化范围为92.51~405.74 m(均值为199.06 m),明显小于排水沟渠长度(也就是2.5 km),表明沟渠具有较强的NO_3~--N滞留潜力.M-M方程较好地拟合了NO_3~--N吸收动力学特征,参数Umax变化范围为158~1 280μg·(m~2·s)~(-1)[均值为631.13μg·(m~2·s)~(-1)],Km变化范围为0.16~5.52 mg·L~(-1)(均值为1.46 mg·L~(-1)).相关分析表明,Sw-amb与NO_3~--Namb呈显著负相关、Uamb与NO_3~--Namb呈极显著正相关,其它螺旋指标与NO_3~--N背景浓度的相关性均不明显;水文因素对NO_3~--N滞留影响也不显著,而沟渠槽道地貌特征指标Фw、ФA与大部分螺旋指标都呈显著相关性,表明槽道地貌特征对NO_3~--N滞留影响相对较为重要.     

TiO2表面沉积Ag粒子及其可见光下降解含盐废水中的苯酚

为了制备可见光激发下能高效降解含盐废水中有机物的光催化剂,首次以商用TiO_2光催化剂(P25)为载体,利用吸附相反应技术一步获得了Ag沉积的可见光响应复合光催化剂.同时,通过XPS、TEM、HRTEM及紫外可见漫反射光谱图,结合多种高含盐水体系中苯酚的光催化降解过程,研究了不同Ag沉积对催化剂可见光活性的影响.结果发现,吸附平衡后P25表面富含水的吸附层可作为反应和粒子的生成场所,生成量子尺寸的Ag粒子.另外,在吸附层中生成的Ag粒子均匀分布于P25表面并与之紧密结合,并在TiO_2晶格结构中引入晶格交错结构.Ag与TiO_2的表面等离子体共振效应和晶格交错结构共同提升了催化剂的可见光响应和电荷的分离效率,增强了催化剂对苯酚的可见光催化性能.在含盐废水体系中,盐离子数量越多,催化剂在可见光下降解苯酚过程受到的干扰越大.     

藻类光竞争模型构建及水体紊动对竞争的影响

光是藻类进行光合作用的重要能量来源,决定藻类的初始生产力,当多种浮游藻类共同生存时,会一起竞争光强.光竞争能力强的浮游藻类浓度增加,光竞争能力较弱的则减少,从而完成水体中浮游藻类优势藻的替代.本文通过在以往建立的单藻模型的基础上,耦合入竞争模型,构建两种（多种）浮游藻类光竞争模型,尝试通过数值模拟,研究不同水体紊动中竞争藻属分别取得竞争优势的机理.模拟结果表明：稳态水体中,竞争藻属的自身垂向迁移决定藻浓度的垂向分布,具有浮力调节能力的微囊藻属占据上层水体优势地位,并取得竞争优势;动态水体中,竞争藻属垂向分布均较为均匀,生长速率决定藻的竞争优势,小球藻属生长速率快,最终易取得竞争优势.此外,考虑浮游藻属的动态自遮蔽,会加速稳态水体中微囊藻属取得竞争优势,并限制动态水体中小球藻属的无限制生长,使得模拟结果更加符合实际情况.     

FMEA and consideration of real work situations for safer design of production systems

Production equipment designers must ensure the health and safety of future users; in this regard, they augment requirements for standardizing and controlling operator work. This contrasts with the ergonomic view of the activity, which recommends leaving operators leeway (margins for manoeuvre) in performing their task, while safeguarding their health. Following a brief analysis of design practices in the car industry, we detail how the Failure Modes and Effects Analysis (FMEA) approach is implemented in this sector. We then suggest an adaptation that enables designers to consider real work situations. This new protocol, namely, work situation FMEA, allows experience feedback to be used to defend the health standpoint during designer project reviews, which usually only address quality and performance issues. We subsequently illustrate the advantage of this approach using two examples of work situations at car parts manufacturers: the first from the literature and the second from an in-company industrial project.     

基于地域性的三种污泥干化工艺的经济性比较

随着城市污水排放量的增多和成分的复杂化,污泥处理已成为污水处理厂面临的最大难题。脱水污泥含水率高,不利于后续的处理与再利用。污泥热干化可将污泥含水率降至10%~40%,但该过程耗能大,会大幅增加污泥处理成本,不利于污泥处理技术的推广应用。以拉萨、上海、重庆为例,分别对带式干化、热泵-太阳能干化、热泵-太阳能-蓄热干化3种污泥干化工艺的经济性进行分析,阐明了不同干化方式的适用特点,为相变蓄热技术在污泥干化中的推广应用提供了技术参考。     

浅析西吉县党家岔震湖形成原因及其对社会生活影响

现存于宁夏回族自治区固原市西吉县内、以党家岔震湖为代表的43个串珠状堰塞湖是由1920年海原大地震诱发而成。试图从土壤地貌、地形地势和水文河流三个方面对西吉县党家岔震湖形成原因予以分析,借此探究引发地震堰湖所必要的自然条件因素;另外结合史实情况,以居住方式、精神文化和经济发展三个角度来进一步揭示震湖"由无到有"这一自然环境变迁过程对当地社会生活所产生的影响,进而有益于对相关区域未来发展前景给予指导。     

测土配方施肥对湖北省N2O减排的贡献

为弄清测土配方施肥项目实施后对氧化亚氮(N_2O)排放产生的影响及其带来的经济效益.本研究通过比较传统施肥和测土配方推荐施肥的农田氮(N)投入量,依据《2006年IPCC国家温室气体清单指南》方法,分别估算了农田N_2O的直接排放和间接排放.结果表明,测土配方施肥项目从2004年开始实施至2013年的10年时间里,共减少氮肥的施用量74.39×104t(折纯N),作物产量增加1898.05×104t;10年里共减少N_2O排放总量为2.24×104t,其中由氮肥施用量减少带来的N_2O减排量为1.57×104t,作物产量提高带来的N_2O减排量为0.67×104t;湖北省不同区域的N_2O减排量与该地区项目实施面积密切相关,项目实施10年来襄阳市N_2O减排总量最大,为0.31×104t,其次是荆州市,减排量为0.26×104t,神龙架林区N_2O减排总量最小,仅为0.0034×104t;不同作物对N_2O减排的贡献以玉米减排总量最大,为0.54×104t,占减排总量的24.17%,其次为水稻,减排量为0.49×104t,芝麻减排总量最小,仅0.018×104t.按照湖北省碳交易市场最新交易价格25元·t-1C来计算,湖北省实施测土配方施肥项目10年来仅N_2O减排所带来效益可达1.74亿元.测土配方施肥项目不仅在湖北省粮食增产上有重要贡献,对减少N_2O排放也有重要贡献,并带来一定的经济效益.     

鞍山市供水水质安全面临的问题与保障对策

从生活饮用水质安全的角度评价了鞍山市供水水质的安全现状，分析了鞍山市供水水质安全面临的各种挑战，探讨了影响水质安全的主要问题，并提出对鞍山市水质安全的保障对策和技术措施。     

Implementing the Protocol on Environmental Protection to the Antarctic Treaty: Future applications of geographic information systems within the Committee for Environmental Protection

With the entry into force of the Protocol on Environmental Protection to the Antarctic Treaty (the Protocol) in January 1998, key operational aspects of the newly established Committee for Environmental Protection (CEP), such as its advisory capacity to Antarctic Treaty Consultative Meetings (ATCMs) need to be urgently addressed. This paper advocates the use of a geographic information system (GIS) environmental database to reinforce the advisory capacity of the CEP. The demonstrated links between the provisions of the Protocol and GIS capabilities illustrate the potential this has to assist the CEP in delivering informed advice to ATCMs. The range of GIS applications that could be utilized by the CEP in fulfilling its functions are examined by reference to precedents in Europe (CORINE) and Australia (ARIS).     

Assessing the strength of climate and land-use influences on montane epiphyte communities

Epiphytes, air plants that are structurally dependent on trees, are a keystone group in tropical forests; they support the food and habitat needs of animals and influence water and nutrient cycles. They reach peak diversity in humid montane forests. Climate predictions for Central American mountains include increased temperatures, altered precipitation seasonality, and increased cloud base heights, all of which may challenge epiphytes. Although remaining montane forests are highly fragmented, many tropical agricultural systems include trees that host epiphytes, allowing epiphyte communities to persist even in landscapes with lower forest connectivity. I used structural equations models to test the relative effects of climate, land use, tree characteristics, and biotic interactions on vascular epiphyte diversity with data from 31 shade coffee farms and 2 protected forests in northern Nicaragua. I also tested substrate preferences of common species with randomization tests. Tree size, tree diversity, and climate all affected epiphyte richness, but the effect of climate was almost entirely mediated by bryophyte cover. Bryophytes showed strong sensitivity to mean annual temperature and insolation. Many ferns and some orchids were positively associated with bryophyte mats, whereas bromeliads tended to establish among lichen or on bare bark. The tight relationships between bryophytes and climate and between bryophytes and vascular epiphytes indicated that relatively small climate changes could result in rapid, cascading losses of montane epiphyte communities. Currently, shade coffee farms can support high bryophyte cover and diverse vascular epiphyte assemblages when larger, older trees are present. Agroforests serve as valuable reservoirs for epiphyte biodiversity and may be important early-warning systems as the climate changes.