不同龄级南川木波罗幼苗生物量及分配格局

以不同龄级（1~5年生）南川木波罗幼苗为研究对象,研究其生物量及分配,并利用苗高（H）、基径（D）及HD2估测单株木及其器官生物量的适合模型。结果表明：（1）随着苗龄的增加,单株生物量及各器官生物量随之增加,其中枝生物量增加幅度最大;（2）地上部分各器官生物量分配率表现为：干生物量>叶生物量>枝生物量;（3）地下部分各龄级根系生物量分配以主根和粗根为主,表现为：主根>粗根>细根,地上部分生物量分配率高于地下部分,并最后趋于稳定;（4）以基径(D)作为自变量优于利用株高(H)和HD2建立生物量预测模型,并且多以幂函数为最佳,建立的生物量预测模型中,除细根生物量预测模型较差外,其它预测模型效果都较好,相关系数均达到极显著水平,表明利用本文建立的估测南川木波罗各器官生物量模型是可行的     

Effects of iron oxide nanoparticles on phenotype and metabolite changes in hemp clones (Cannabis sativa L.)

● Fe₃O₄ NPs increased the biomass and chlorophyll content of hemp clones. ● Fe₃O₄ NPs penetrated and were internalized by root cells. ● Fe₃O₄ NPs induced the alteration of metabolite profiles in hemp leaves. ● The psychoactive compound THC in hemp leaves was significantly down-regulated. We investigated the effect of iron oxide nanoparticles (Fe₃O₄ NPs, ~17 nm in size) on the phenotype and metabolite changes in hemp (Cannabis sativa L.), an annual crop distributed worldwide. Hemp clones were grown in hydroponic cultures with Fe₃O₄ NPs (50, 100, 200, or 500 mg/L) for four weeks. TEM and ICP-MS were used to determine Fe₃O₄ NPs uptake and translocation. LC-MS-based metabolomics was employed to explore the deep insight into the effect of Fe₃O₄ NPs on hemp plants. The results revealed that plant growth enhanced gradually with increasing concentrations of given NPs up to 200 mg/L, which improved the fresh weight and dry weight by 36.13% and 74.68%, respectively, compared to the control. Even at a high dose (500 mg/L), Fe₃O₄ NPs promoted plant growth, including increased biomass and tissue length. NPs significantly increased the iron and chlorophyll content in plant tissues Increased catalase activity and reduced hydrogen peroxide content in hemp leaves suggested that the Fe₃O₄ NPs activated the defense system. TEM showed that NPs were abundantly attached to the cell wall and dispersed throughout the root cells. Metabolomics revealed that Fe₃O₄ NPs induced metabolic reprogramming in hemp leaves, including the up-regulation of carbohydrates and organic acids, and down-regulation of antioxidants, especially tetrahydrocannabinol (THC). The significantly up-regulated metabolites, including peonidin and 2-hydroxycinnamic acid, could be involved in photosynthesis in hemp plants. These results demonstrate the potential of Fe₃O₄ NPs for promoting hemp growth and decreasing the THC content at low doses.     

Degradation of sulfadiazine by UV/Oxone: roles of reactive oxidative species and the formation of disinfection byproducts

Environmental Science and Pollution Research - Sulfadiazine (SDZ) is a typical persistent sulfonamide antibiotic, which has been widely detected in natural drinking water sources. The degradation...     

Construction of double tube granular sludge microbial fuel cell and its characteristics and mechanism of azo dye degradation

Environmental Science and Pollution Research - Microbial fuel cells (MFCs) can obtain electrical energy from extensive organic matter and complete wastewater treatment at the same time. The...     

A new method for broad-scale modeling and projection of plant assemblages under climatic,biotic, and environmental cofiltering

There is increasing interestin broad-scale analysis, modeling, and prediction of the distribution and composition of plant species assemblages under climatic, environmental, and biotic change, particularly for conservation purposes. We devised a method to reliably predict the impact of climate change on large assemblages of plant communities, while also considering competing biotic and environmental factors. To this purpose, we first used multilabel algorithms in order to convert the task of explaining a large assemblage of plant communities into a classification framework able to capture with high cross-validated accuracy the pattern of species distributions under a composite set of biotic and abiotic factors. We applied our model to a large set of plant communities in the Swiss Alps. Our model explained presences and absences of 175 plant species in 608 plots with >87% cross-validated accuracy, predicted decreases in α, β, and γ diversity by 2040 under both moderate and extreme climate scenarios, and identified likely advantaged and disadvantaged plant species under climate change. Multilabel variable selection revealed the overriding importance of topography, soils, and temperature extremes (rather than averages) in determining the distribution of plant species in the study area and their response to climate change. Our method addressed a number of challenging research problems, such as scaling to large numbers of species, considering species relationships and rarity, and addressing an overwhelming proportion of absences in presence–absence matrices. By handling hundreds to thousands of plants and plots simultaneously over large areas, our method can inform broad-scale conservation of plant species under climate change because it allows species that require urgent conservation action (assisted migration, seed conservation, and ex situ conservation) to be detected and prioritized. Our method also increases the practicality of assisted colonization of plant species by helping to prevent ill-advised introduction of plant species with limited future survival probability.     

植物病虫害的遥感探测

本文概述了应用遥感技术探测植物病虫害的原理、途径、优缺点与发展过程.着重报导了最近在安徽省孤山林场开展的从TM图象提取森林松毛虫害的成功试验,并展望了应用遥感技术提高植物病虫害防治水平的前景.     

Solute transport properties of compacted Ca-bentonite used in FEBEX project

The present Spanish concept of a deep geological high level waste repository includes an engineered clay barrier around the canister. The clay presents a very high sorption capability for radionuclides and a very small hydraulic conductivity, so that the migration process of solutes is limited by sorption and diffusion processes. Therefore, diffusion and distribution coefficients in compacted bentonite (i.e. in "realistic" liquid to solid ratio conditions) are the main parameters that have to be obtained in order to characterise solute transport that could be produced after the canister breakdown. Through-Diffusion (TD) and In-Diffusion (ID) experiments with HTO, Sr, Cs and Se were carried out using compacted FEBEX bentonite, which is the reference material for the Spanish concept of radioactive waste disposal. Experiments were interpreted by means of available analytical solutions that allow the estimation of diffusion coefficients and, in some cases, distribution coefficients. Analytical solutions are simple to use, but rely on hypotheses that do not hold in all the experiments. These experiments were interpreted also using an automatic parameter estimation code that overcomes the limitations of analytical solutions. Numerical interpretation allows the simultaneous estimation of porosity, diffusion and distribution coefficients, accounts for the role of porous sinters and time-varying boundary concentrations, and can use different types of raw concentration data.     

Novel synthetic approaches and TWC catalytic performance of flower-like Pt/CeO2

A novel Ultrasonic Assisted Membrane Reduction （UAMR）-hydrothermal method was used to prepare flower-like Pt/CeO2 catalysts. The texture, physical/chemical properties, and reducibility of the flower-like Pt/CeO2 catalysts were characterized by X-Ray Diffraction （XRD）, Scanning Electron Microscope （SEM）, Transmission Electron Microscope （TEM）, N2 adsorption, and hydrogen temperature programmed reduction （HE-TPR） techniques. The catalytic performance of the catalysts for treating automobile emission was studied relative to samples prepared by the conventional wetness impregnation method. The Pt/CeO2 catalysts fabricated by this novel method showed high specific surface area and metal dispersion, excellent three-way catalytic activity, and good thermal stability. The strong interaction between the Pt nanoparticles and CeO2 improved the thermal stability. The Ce4＋ ions were incorporated into the surfactant chains and the Pt nanoparticles were stabilized through an exchange reaction of the surface hydroxyl groups. The SEM results demonstrated that the Pt/CeO2 catalysts had a typical three-dimensional （3D） hierarchical porous struc- ture, which was favorable for surface reaction and enhanced the exposure degree of the Pt nanoparticles. In brief, the flower-like Pt/CeO2 catalysts prepared by UAMR-hydrothermal method exhibited a higher Pt metal dispersion, smaller particle size, better three-way catalytic activity, and improved thermal stability versus conven- tional materials.     

中国电子废物处理处置典型地区污染调查及环境、生态和健康风险研究进展

电子废物含有大量的金属、塑料和阻燃剂等物质,如果处理不当,电子废物将向环境排放种类繁多的有毒有害物质,从而产生严重的环境污染问题。近年来,国内外学者对电子废物处理所致的生态环境问题给予了相当的关注,已经开展了不少相关研究,这些研究主要集中在我国的几个电子废物处理处置典型地区。本文对近5年来的相关研究成果进行了系统综述,内容涉及电子废物处理处置过程中产生的主要环境污染物,电子废物处理处置活动所致的土壤、水体和大气的重金属和持久性有机污染物污染以及电子废物处理处置活动对动植物和人体的污染风险等,并提出将来关于电子废物研究中需要关注的问题。     

Liquefaction of sawdust in hot compressed ethanol for the production of bio-oils

Direct liquefaction of lignocellulosic waste (sawdust) has been conducted in hot-compressed ethanol at temperatures from 150 to 250 °C. It was found that polyols such as glycerol, glycol and polyethylene glycol (PEG) promoted liquefaction process assisted with hot ethanol treatments seemed promising for production of bio-oils from lignocellulosic materials. Effects of different solvents and catalysts on liquefaction of sawdust were investigated. The results showed that the optimum operating condition for catalytic liquefaction is at 250 °C, 1 h of reaction time using glycerol and ethanol as solvent where operating at this condition realized the highest conversion of sawdust which is 97.8%. After reaction, the liquified product was separated by vacuum distillation. Two fractions were obtained, namely light oil and heavy oil. The properties and compositions of these two fractions were characterized in terms of Fourier transform infrared spectroscopy (FT-IR), gas chromatography–mass spectrometry (GC–MS), size exclusion chromatography (SEC) and nuclear magnetic resonance (NMR).