沼液淹没土壤抑制根结线虫及对土壤线虫群落的影响

为探索沼液抑制根结线虫的效果,本研究通过盆栽试验,以番茄为试供作物,对比了种植前沼液淹没土壤(BSS)、种植期间浇灌沼液(BS)和加热(HE)3种方法对根结线虫的防控效果。结果表明,与不采取任何措施的对照(CK)处理相比, BSS处理抑制根结线虫效果最为明显,防效高达97.1%,根结指数分别比HE和BS处理降低96.9%和92.9%。HE处理尽管在处理土壤后显著降低了根结线虫数量,但在最后破坏性取样时(结束试验)出现反弹,根结线虫数量甚至高于CK处理。对于土壤线虫群落,CK处理中以植食性线虫为主(81.8%);两个沼液处理中食细菌线虫占优势(平均78.3%),且其中的杂食捕食性线虫在土壤前处理后消失,在试验结束时又重新出现,但所占比例依然非常低。沼液淹水方式的高效防控效果揭示了利用沼液防控根结线虫的关键期在于线虫入侵到植物根部之前的幼虫期。然而,在盆栽系统中,沼液淹水的方式也对作物生长表现出了一定的抑制趋势。高量沼液施用防控病害的同时引发的植物毒害作用以及环境污染风险,需要进一步开展田间研究。     

Effect of organic amendment amount on soil nematode community structure and metabolic footprints in soybean phase of a soybean-maize rotation on Mollisols

It has been well documented that organic amendment affects soil nematode community structure. However, little is known about the effect of organic amendment amount on soil nematodes. To assess the effect of the amount of organic amendments on soil nematode community structure and metabolic activity, the community composition, abundance, and metabolic footprints of soil nematodes were determined in a long-term field experiment with various amounts of organic amendment in Northeast China. Fertilization treatments included an unfertilized control (CK), chemical fertilizer without manure amendment (OM₀), manure applied at 7.5 Mg ha^-1 plus chemical fertilizer (OM₁), and manure applied at 22.5 Mg ha^-1 plus chemical fertilizer (OM₂). A total of 46 nematode genera were found. Treatments with the largest amount of organic amendment had the smallest number of plant parasite genera (5), but a largest number of dominant genera (7). Soil nematodes, bacterivores, and fungivores were the most abundant in OM₂, followed by OM₁, and the lowest in OM₀ and CK. Organic amendment increased the enrichment index (EI), and the large amount of organic amendment increased the metabolic footprints of bacterivore (Baf) and fungivore (Fuf) and enrichment footprint (Ef). The relationships between Baf (or Fuf) and the increases in soil organic carbon (ΔSOC) and total nitrogen (ΔTN) were stronger than those of bacterivore (or fungivore) abundance with ΔSOC and ΔTN, except for the relationship between bacterivore abundance and ΔSOC. The EI and Ef were positively correlated with ΔSOC and ΔTN. These findings suggest that the amount of organic amendment affects soil nematode activity and function at entry levels in soil food web, and that metabolic footprints of soil nematodes may be better indicators than their abundances in assessing their relationships with soil nutrients.     

Retrospective analysis of the influence of environmental drivers on commercial stocks and fishing opportunities in the Irish Sea

Irish Sea fisheries have undergone considerable change in recent years following the decline of commercially important finfish stocks and their slow response to management's recovery plans. In 2015, the fishing industry called for a holistic exploration into the impact of environmental change and food web effects to identify the drivers underpinning stock dynamics. In this study, we identify correlations between large‐scale climatic indicators, temperature, primary and secondary productivity, and fish recruitment in the Irish Sea and incorporate them into an Ecopath with Ecosim food web model co‐created by scientists and fishers. Negative correlations were found between the North Atlantic Oscillation winter index (NAOw) and large zooplankton abundance and between the Atlantic Multidecadal Oscillation (AMO) and the recruitment of cod (Gadus morhua) and whiting (Merlangius merlangus). Using correlation analyses to direct the addition of environmental drivers to the Irish Sea ecosystem model improved the models fit against observed biomass and catch data and revealed the indirect impacts of environmental change as mitigated through trophic interactions. Model simulations suggest that historic environmental change suppressed the overall production of commercial finfish, limiting opportunities for the fishing industry, whilst also dampening the rate of stock recovery despite marked reductions in fishing effort. These results suggest that failure to account for ecosystem information may lead to misconceived expectations and flawed fisheries management; therefore, there is a need to operationalize ecosystem information through management procedures to support fisheries advice.     

海洋食物网结构稳定性及干扰响应研究综述

针对当前全球环境急剧变化的背景,本文归纳了海洋食物网结构复杂性常用的量化指标,梳理了食物网稳定性不同维度的概念并深入探究其与复杂性之间的内在联系。根据海洋生态系统的不同干扰类型,分析了各种类型干扰的发生方式以及食物网在应对干扰时的适应机理,最后总结了海洋生态系统数据获取分析以及食物网构建时有待解决的问题,并指出开展初级生产者与消费者之间的相互作用研究能更利于解析全球变化对海洋食物网结构和功能的影响。     

基于稳定同位素技术的天津大神堂海域人工鱼礁区食物网结构研究

本研究对2016年6月在天津大神堂3个礁区(2010年建成的鱼礁区；2012年建成的鱼礁区；2014年建成的鱼礁区)和对照区域采集的生物消费者及其食物源样品的碳、氮稳定同位素组成进行了分析，通过IsoSource模型计算不同区域生物的食物网基础，并利用氮稳定同位素数据计算消费者的营养级。结果显示，根据δ13C值可以将其食物源分为浮游植物、悬浮颗粒有机物(POM)和沉积相颗粒有机物(SOM)三类；浮游植物对消费者的碳源贡献率(67.2%~81.5%)最大，是大神堂海域的生物食物网的基础。不同区域同一食物源的δ13C和δ15N值没有显著性差异；礁区内滤食性贝类毛蚶(Arca subcrenata)、菲律宾蛤仔(Ruditapes philippinarum)和长牡蛎(Crassostrea gigas)的δ13C值显著高于对照区，作为潜在碳源的浮游植物对其的贡献率显著增加。消费者的δ15N值则介于7.70‰~14.34‰之间，消费者的营养级介于2.0~3.95级之间。游泳生物食性生物的δ15N和营养级在礁区内有所提高，礁区建成的年份越长，其营养级与对照区域的差别越显著。稳定同位素研究表明，人工鱼礁建设可能导致鱼礁区内滤食性生物的食物来源组成改变，并提高游泳生物食性生物的营养级。     

Assessment of the effect of silver nanoparticles on the relevant soil protozoan genus Acanthamoeba

Silver nanoparticles (AgNP) are used in a broad range of consumer products and industrial applications. During the regular product life cycle and disposal, AgNP are continuously released into the environment. Hence, the aim of this study was to investigate the potential ecotoxicological effects of AgNP exposure on amoebae. The Acanthamoeba castellanii ATCC 30234 strain and environmental isolate Acanthamoeba strain C5/2, which are both affiliated with genotype T4, were chosen as representatives of ecologically important soil protozoan organisms. The amoebae were exposed to citrate‐stabilized AgNP (30 and 70 nm in size) for 24 h and 96 h at concentrations ranging from 600 µg L⁻¹ to 20 mg L⁻¹. A newly adopted cell culture based microscopic assay was applied to assess the adherence ability of the amoeba trophozoites. The general metabolic activity of Acanthamoeba was determined to be a second independent endpoint by means of intracellular reduction of the redox dye AlamarBlue®. The fate of AgNP within the amoebae and test solutions was visualized by light‐ and transmission electron microscopy (TEM). Both Acanthamoeba strains showed a significant dose‐dependent decrease of adherence ability (p  < 0.04) and metabolic activity (p < 0.01) after 96 h of AgNP exposure. The environmental Acanthamoeba strain C5/2 lost both its adherence ability and metabolic activity at lower AgNP concentrations than the type strain, indicating a higher sensitivity to ionic silver. This was confirmed by the application of AgNO₃, provoking a higher effect level in strain C5/2. AgNP was visualized intracellularly by transmission electron microscopy within the cytoplasm of Acanthamoeba . This is the first report to show the ecotoxicological effects of short‐term AgNP exposure on the soil protist Acanthamoeba , causing both changes in the adherence ability and metabolic activity of this amoeba. This combined approach may be a powerful tool in the future for predicting potential harmful ecotoxicological effects of AgNP exposure using soil protozoans.     

基于Web内嵌Office控件的文档管理平台研究

阐述了基于web内嵌office控件的文档管理平台的基本框架结构,详细介绍了利用web-office控件实现模板的创建和文档的创建的设计原理,以及整个文档管理平台模块的详细功能实现。     

Cause Analysis and Treatment Measure on Cracks in New Reinforced Concrete Restricted by Old Web Concrete

In this paper, the cause analysis about cracks on the new concrete web poured in multi -span continuous box -girder of a main bridge was introduced. This bridge is a prestressed concrete one with variable cross sections and an 80 -meter main span. When casting reinforced concrete in large volume in box girder during vehicle transport service, the shrinkage cracks in cast -in place reinforced web concrete were formed due to the restriction of old web concrete. Then, the control measure taken on these cracks is discussed.     

Composition of Application Based on Business Rule

In order to support flexibility and reusability of application composition based on Internet,with business rule and Aspect-Oriented Programming(AOP) which divides a business process into a control business process and a core business process,the authorsgive composition mechanism.A technique of implementation is analyzed.At last,the primary application of the above work in Chongqing of China is introduced,as well as some effects acquired.     

一种农业电网远程监测系统的设计

基于当前嵌入式的流行，设计了一套嵌入式网络服务器，对其设计方案及主要芯片端口和功能进行介绍，将其应用到农业电网远程监测系统中的网络通信，给出了系统的功能框图，所涉及到的技术有数据采集技术、实时网络通讯技术等等。