Detection of intermediates in the TiO2-assisted photodegradation of Rhodamine B under visible light irradiation

The photocatalytic degradation of dye Rhodamine B （RhB） in the presence of TiO2 nanostdpe or P25 under visible light irradiation was investigated. The degradation intermediates were identified using Infrared spectra （IR spectra）, ^1H nuclear magnetic resonance （^1HNMR） spectra, and gas chromatography-mass spectroscopy （GC-MS）. The IR and the ^1HNMR results showed that the large conjugated chromophore structure of RhB was efficiently destroyed under visible light irradiation in both the photocatalytic systems （TiO2 nanostfipe or P25 and Rhodamine B systems）. GC-MS results showed that the main identified intermediates were ethanediotic acid, 1,2-benzenedicarboxylic acid, 4-hydroxy benzoic acid and benzoic acid, which were almost the same in the TiO2 nanostdpes and P25 systems. This work provides a good insight into the reaction pathway（s） for the TiO2-assisted photocatalytic degradation of dye pollutants under visible light irradiation.     

Degradation of bisphenol-A using ultrasonic irradiation assisted by low-concentration hydrogen peroxide

This study investigated the degradation of bisphenol-A (BPA) by ultrasonic irradiation in the presence of different additives (H2O2,air bubbles and humic acid) under various operating conditions,i.e.,ultrasonic frequency,power intensity and power density.The results demonstrated that the BPA degradation followed pseudo first-order kinetics under different experimental conditions.The optimum power intensities were 0.9,1.8,and 3.0W/cm 2 at the frequencies of 400,670,and 800 kHz,respectively.At the fixed frequ...     

Factors affecting the adoption of multiple climate‐smart agricultural practices in the Indo‐Gangetic Plains of India

Climate change poses a major threat to agricultural production and food security in India, and climate‐smart agriculture (CSA) is crucial in addressing the potential impacts. Using survey data from 1,267 farm households in 25 villages from Bihar and Haryana in the Indo‐Gangetic Plains, this study analyzes the factors that determine the probability and level of adoption of multiple CSA practices, including seeds of stress‐tolerant varieties, minimum tillage, laser land leveling, site‐specific nutrient management and crop diversification. We applied a multivariate probit model for the simultaneous multiple adoption decisions, and ordered probit models for assessing the factors affecting the level of adoption. The adoption of the various CSA practices is interrelated, whereas several factors, including household characteristics, plot characteristics, market access and major climate risks are found to affect the probability and level of CSA adoption. Climate‐smart agriculture (CSA) adoption and its intensity also vary significantly between eastern Bihar, which is relatively poor and densely populated, and north‐western Haryana. Engaging multiple stakeholders such as farmers, agricultural institutions, agricultural service providers and concerned government departments at the local level is crucial for the large‐scale uptake of CSA. The study, therefore, calls for agricultural policy reforms so that most of the issues related to the uptake of CSA can be adequately addressed.     

A Cost‐Effective Laser Scanning Method for Mapping Stream Channel Geometry and Roughness

This brief pilot study implements a camera‐based laser scanning system that potentially offers a viable, cost‐effective alternative to traditional terrestrial laser scanning (TLS) and LiDAR equipment. We adapted a low‐cost laser ranging system (SICK LSM111) to acquire area scans of the channel and bed for a temporarily diverted stream. The 5 m × 2 m study area was scanned at a 4 mm point spacing which resulted in a point cloud density of 5,600 points/m². A local maxima search algorithm was applied to the point cloud and a grain size distribution of the stream bed was extracted. The 84th and 90th percentiles of this distribution, which are commonly used to characterize channel roughness, were 90 mm and 109 mm, respectively. Our example shows the system can resolve both large‐scale geometry (e.g., bed slope and channel width) and small‐scale roughness elements (e.g., grain sizes between about 30 and 255 mm) in an exposed stream channel thereby providing a resolution adequate for the estimation of ecohydraulic roughness parameters such as Manning's n. While more work is necessary to refine our specific field‐deployable system's design, these initial results are promising in particular for those working on a limited or fixed budget. This opens up a realm of laser scanning applications and monitoring strategies for water resources that may not have been possible previously due to cost limitations associated with traditional TLS systems.     

Fe-Ni-Si三元合金辐照诱发的Ni-Si团簇形核及生长演变机制

目的 探索辐照条件下Ni与Si元素的相互作用对RPV合金中团簇形成演变的影响.方法 对PRV合金的三元模型合金Fe-Ni-Si做离子辐照实验,并采用原子探针技术对团簇进行分析,采用纳米压痕技术进行硬度分析.结果 纳米压痕的结果表明,材料的硬度随辐照剂量的升高而增大.原子探针结果表明,辐照后材料中产生了Ni-Si溶质团簇...     

Evaluation and sensitivity of cyanobacteria,Nostoc muscorum and Synechococcus PCC 7942 for heavy metals stress – a step toward biosensor

This study attempted to determine the effects of heavy metals on the photosynthetic blue-green algae for their potential to use as a biosensor. The bioaccumulation of metals and its effects on pigments of Nostoc muscorum and Synechococcus PCC 7942 were assessed. The culture was grown in BG 11 liquid medium supplied with different metals like mercury (Hg), lead (Pb), and cadmium (Cd) and incubated (µM 20 concentrations) for 10 days under optimal conditions. The accumulated amounts of metals were determined by atomic absorption spectroscopy (AAS). The stress effects on photosynthetic pigment chlorophyll a (Chl a) were monitored by laser-induced fluorescence (LIF). Bio-concentration factor (BCF) reached a peak in cells on the 2nd day of incubation followed by a gradual reduction. The highest reduction in the pigment concentrations (Chl a and β carotene) was observed at 20?µM?L^?1 Hg treatment. The results indicate that, cyanobacteria may serve as both potential species to be used as a biosensor and used to clean up heavy metals from contaminated water. These changes were analyzed with the long-term goal of exploiting cyanobacterial cells as biosensors.     

应用高效离子交换色谱分析青枯菌的致病力分

应用高效离子交换色谱和激光光散射仪检测器对不同致病力的青枯菌进行分析,建立了一种快速检测青枯菌致病力分化的新方法青枯菌纯培养物经过高效离子交换色谱分离得到3个致病力不同的特征峰,大小依次为峰3组分>峰2组分>峰1组分.对10株青枯菌进行色谱分析,并结合番茄组培苗感染试验检测其致病力,结果发现,强致病力菌株经过色谱分离只在峰3的保留时间位置出现单一特征峰,在9 d内即可引起100%的番茄组培苗发病;若菌株经过色谱分离形成3个特征峰,则峰3所占的面积比越大,该菌株的致病性相对就越强.25株不同致病力青枯菌的验证试验表明了该方法的可行性,番茄组培苗发病率x与峰3面积比y之间呈现出良好的线性关系,回归方程y=0.9581x+5.4984,相关系数r=0.986.通过对青枯菌色谱行为、致病力、细胞表而黏附的EPS Ⅰ含量三者之间相互关系的进一步研究,发现青枯菌的致病力越强,则细胞表面黏附的EPSⅠ越多,峰3所占的面积比就越大.图3表6参15     

Statistical modeling of radiolytic (60Co g) degradation of Ofloxacin,antibiotic: Synergetic effect,kinetic studies & assessment of its degraded metabolites

Linear, interactive and quadratic effects of process parameters were studied. Degradation of Ofloxacin (Ofx) was related with G value of irradiation process. The synergistic effect of H₂O₂ on lower dose of g-irradiation was established. The process follows pseudo first order with dose constant (d = 0.232 kGy^–1). The impact of human activities in the past few decades has paved the way for the release of pollutants due to the improper effluent treatment. Recent studies revealed that, Ofloxacin, an antibiotic as one of the major pollutant affecting surface water and ground water. In this study, the radiolytic potential of Ofloxacin was investigated. The effects of pH, dose and concentration of Ofloxacin were analyzed using One Factor At a Time (OFAT) and the interactive effects between the parameters were studied using Face Centered Central Composite Design. The statistically optimised developed model shows 30% degradation at initial antibiotic concentration of 1mM at pH 3.0 and at 2 kGy dose of gamma ray. The process efficiency was evaluated in terms of G value and its correlation with the concentration of antibiotic was also established. The process of degradation was augmented by the addition of H₂O₂ (1.5 mM). The reaction kinetics for the process was evaluated, the dose rate constant and the rate of degradation for the augmented process was found to be 0.232 kGy^-1 and 0.232 mM/kGy, respectively. The degraded metabolites of the radiolytic degradation of Ofloxacin were analyzed through change in pH, reduction in TOC and GC-MS spectrum.     

γ-射线辐照对太湖原水中越冬蓝藻复苏的抑制

采用60Co衰变产生的γ-射线辐照太湖原水,研究其对水中越冬蓝藻复苏的抑制,分析不同吸收剂量和添加物(甲醇、碳酸钠)对抑制效果的影响.结果表明,γ-射线辐照能有效抑制太湖水中越冬蓝藻的复苏,吸收剂量越大,抑制蓝藻复苏的效果越好.吸收剂量为5kGy的水样,培养40d,水中叶绿素a(Chl-a)、叶绿素b(Chl-b)和藻蓝素(PC)含量分别为对照样的8.66%、16.8%和17.2%,抑制了越冬蓝藻的复苏.0.5%甲醇和0.22mmol/LNa2CO3添加物抑制了辐照过程,与不含添加物水样相比,相同吸收剂量下,相同培养时间内,含添加物水样中Chl-a、Chl-b和PC浓度较高.     

基于激光扫描和无人机倾斜摄影的露天采场安全监测应用

为解决露天采场安全监测中观测困难、效率低下等问题,结合引用三维激光扫描和无人机倾斜摄影等三维测量技术开展露天采场安全监测融合应用研究。通过应用研究表明:2类技术结合应用可实现露天采场生产环境信息完整三维数据采集;通过统一控制点坐标系和基于点云特征点的迭代最临近点配准算法（ICP）可有效融合2类点云数据,能构建高时效、高精度、高分辨率的采场三维点云模型;融合的三维模型能直观再现采场生产环境,多尺度精准监测安全隐患问题,有效辅助采场生产安全规划;该技术方案弥补了人工安全监测缺陷,提高了安全监测效率,可适用于矿山尾矿库、水电大坝等其他危险源安全监测应用。