A review of fractionations of rare earth elements in plants

Studies were carried out on several aspects of rare earth elements （REEs）, such as the theory and practice of their applications in agriculture, their geochemical behaviors in natural and agricultural ecosystems, the mechanisms for the increase of crop yield using REE fertilizer, and their toxicology. However, limited knowledge was available for the transfer processes and the features and mechanisms of distribution and fractionations of REEs inside plants. The characteristics of REE fractionations in plants can be used to ＂trace＂ the pathway of REE transportation from soils （solution） to plants. A better understanding of the mechanisms of REE fractionations was helpful to investigate the controlling factors, including both the internal and the external ones. The characteristics and mechanisms of REE fractionations in plants and their significance were reviewed. Furthermore, the prospect for these fields was discussed, in hope of providing a new way in studying the bioavailability of REEs and heavy metals.

Determination of Elements by Atomic Absorption Spectrometry in Medicinal Plants Employed to Alleviate Common Cold Symptoms

Eleven important medicinal plants generally used by the people of Turkey for the treatment of common cold have been studied for their mineral contents.Eleven minor and major elements(essential,non-essential and toxic)were identified in the Asplenium adiantum-nigrum L.,Althaea officinalis L.,Verbascum phlomoides L.,Euphorbia chamaesyce L.,Zizyphus jujube Miller,Peganum harmala L.,Arum dioscoridis Sm.,Sambucus nigra L.,Piper longum L.,Tussilago farfara L.and Elettaria cardamomum Maton by employing flame atomic absorption and emission spectrometry and electro-thermal atomic absorption spectrometry.Microwave digestion procedure for total concentration was applied under optimized conditions for dissolution of medicinal plants.Plant based biological certified reference materials(CRMs)served as standards for quantification.These elements are found to be present in varying concentrations in the studied plants.The baseline data presented in this work can be used in understanding the role of essential,non-essential and toxic elements in nutritive,preventive and therapeutic properties of medicinal plants.

Element cycling in the dominant plant community in the Alpine tundra zone of Changbai Mountains, China

Element cycling in the dominant plant communities including Rh. aureum, Rh. redowskianum and Vaccinium uliginosum in the Alpine tundra zone of Changbai Mountains in northeast China was studied. The results indicate that the amount of elements from litter decomposition was less than that of the plant uptake from soil, but that from plant uptake was higher than that in soil with mineralization process released. On the other hand, in the open system including precipitation input and soil leaching output, because of great number of elements from precipitation into the open system, the element cycling(except N, P) in the Alpine tundra ecosystem was in a dynamic balance. In this study, it was also found that different organ of plants had significant difference in accumulating elements. Ca, Mg, P and N were accumulated more obviously in leaves, while Fe was in roots. The degree of concentration of elements in different tissues of the same organ of the plants also was different, a higher concentration of Ca, Mg, P and N in mesophyll than in nerve but Fe was in a reversed order. The phenomenon indicates (1) a variety of biochemical functions of different elements, (2) the elements in mesophyll were with a shorter turnover period than those in nerve or fibre, but higher utilization rate for plant. Therefore, this study implies the significance of keeping element dynamic balance in the alpine tundra ecosystem of Changbai Mountains.

Trace element content of ginger and sage medicinal plants from Algeria

Instrumental Neutron Activation Analysis has been used to make a multi-elemental determi-nation in the Zingiber officinalis and Salvia offi-cinalis, plants used in traditional medicine therapy in Algeria and in most countries. The concentrations of five elements Co, Cr, Sc, Sb and Rb have been determined by long irradiation time with 2.7E13 n?cm–2?s–1 thermal flux using a NUR Algerian Reactor. All these elements are present at trace levels. Their implications in Human health are herein discussed. The quality control of the measurements have been evaluated by analysing a HAY (V-10) IAEA-Standard reference material.

Effect of a High Silver Stress on the Element Transfers from a Smectite-Type Clay Substrate to Plants

Two species of radishes, Raphanus sativus and Raphanus raphanistrum, were grown in the laboratory in the same substrate consisting of a smectite-type clay, which was watered at the beginning of the experience with 50 ml of a solution containing either none or 1000, 2000 or 4000 mg/L of AgNO3, respectively. Occurrence of the toxic metal in the substrate outlines higher element uptakes by the cultivated species Raphanus sativus than by the wild species Raphanus raphanistrum, except for the highest degree of Ag pollution. After a one-month growth in the Ag-polluted substrate, Raphanus sativus was depleted in most of the major, trace and rare-earth elements, except for Al, Fe, Th, Ag and U that increased in the radishes from substrate polluted by 2000 mg/L of AgNO3, and Sr, Co, Ni, U and Ag that increased in the radishes from substrate polluted by 4000 mg/L of AgNO3. Raphanus raphanistrum was enriched in all elements except Si, Na, Rb and K in the polluted substrate. The uptake was monitored by a cation-exchange process in the rhy-zosphere between mineral particles and the watering solution in the presence of various enzymes with specific activities that induced a variable uptake with the REEs being even fractionated. These activities most probably depend on combined factors, such as the plant species, and the chemical and physical properties of the substrate. The results obtained here reveal also that accumulation of nutrient elements and others in the plants is not uniform at a given Ag pollution of the substrate and therefore at a given Ag contamination in the same plant species.

A Comparative Study of Element Cycling in the Soil-Plant System: A Case Study of Shaly and Calcareous Soils, Southern Benue Trough, Nigeria

This study focused on the cycling of major and trace elements in the soil-plant system in parts of Southern Benue Trough, Nigeria. Surface soil samples and cassava crop samples were collected from cultivated farmlands underlined by shaly and calcareous soils and were analysed using standard techniques. The results show that shaly soils are relatively acidic (pH, 4.8 - 6.6) with high level of organic matter content (OM, 3.2% - 8.7%) compared to calcareous soils (pH, 5.6 - 7.2;OM 1.6% - 7.0%). The soils are enriched in elemental composition relative to the world average abundances in soil. The maximum levels of K, Al, and Zn were obtained from shaly soils. The computed accumulation factors are generally <1. Elemental levels decreased in the plant parts in the order tuber > leaf > stem. Significant correlation was obtained between elemental associations of calcareous surface soils compared to that of shaly soils. R-mode factor analysis revealed the controls of soil geochemistry to include lithology, anthropogenic and environmental factors. A stepwise linear regression analysis identified soil elemental component, pH and organic matter as some of the factors influencing soil-plant metal uptake.

农业经济转型视角下饲料产业结构调整对策研究

要实现农业产业的高质量发展就需要积极推动农业经济的转型升级。而饲料产业作为农业经济的重要组成部分,以结构调整的方式提高饲料产业的绿色化、集约化、低碳化发展水平,有利于实现三产融合,进一步提高农业经济的市场竞争力。为此,饲料产业要把握好农业经济转型视角下的机遇,并针对饲料产业存在的挑战提出结构调整对策,从而实现饲料产业的高质量发展。

基于有限元模型的上海市常见园林树种抗风性研究

风害是园林植物受到的主要自然灾害之一,每年由于台风导致的园林树木断枝倒伏等现象频频发生,严重威胁了城市的生态安全。树木形态差异是影响树木稳定性的主要因子,以15种上海市常见园林树木为研究对象,探究不同冠层特征对树木稳定性影响及不同树形对分枝特征变化的敏感性。通过对研究树种的有限元建模进行树木自振和风致破坏模拟,计算得到树木的力学响应特征值,然后结合树木断裂的失效弯矩和树木弯矩在不同风速条件下的变化规律,预测树木断裂的临界风速,结合灾后实地调研结果,综合比较不同树种的抗风能力。

基于OBE理念的课程思政教学实践与评价——以绵阳师范学院“植物生理学”课程为例

“植物生理学”课程是面向生物科学专业本科二年级学生开设的专业主干课程之一.该课程已立项为四川省“一流本科课程”示范课程和绵阳师范学院“课程思政”示范课程.基于0BE理念,根据国家需求、师资需求、创新需求和传承需求,结合学校办学定位和专业人才培养目标,探索课程教学育人和课程思政育人的融合,以期达成专业课程思政教育与专业知识传授和能力培养有机融合的教育教学目标.

基于水系沉积物地球化学背景特征的生态环境评价

本文通过对额尔古纳地区1∶25万区域化探数据分析研究,探讨用水系沉积物地球化学背景特征评价研究区生态环境。参照生态环境地球化学评价方法,对研究区的生态环境进行评价,得出研究区的生态环境总体较好,局部存在轻度至重度污染,并重点圈定了F、As元素土壤污染区域。特征植物营养元素相互间搭配平衡关系较差,说明该区的土壤环境不能很好地为植物生长提供适宜的营养补给条件。测区生命必需元素均在正常范围之内,适宜人类生活和工作。综合分析认为,造成研究区内污染状况的原因可能与矿业开采、人类活动及地质背景等因素有关。区域化探数据结合生态环境地球化学评价方法可以应用于内蒙古生态环境评价。

新时代背景下药用植物学课程教学改革探索

药用植物学是一门和植物资源应用紧密相关的科学。药用植物学人才培养的优化升级,对植物资源丰富的农业大省具有重要的意义。根据多年的教学积累和教学实践,不断更新总结和探索新时代背景下药用植物教学效果的提升方法。通过多维度的教学改革尝试,包括深化实践教学、融入创新思政元素、借鉴国外课程先进理念和聚焦科研对教育创新的引力,旨在提升药用植物学课程教学的效果和增加药用植物学服务地方经济的潜力,提高学生将药用植物学知识应用于实际的能力,为农业大省药用植物资源的开发利用储备人才。

福建连江县5个无居民海岛种子植物区系及地理分布研究

本研究采取样线法和样方法调查相结合的技术路线,对连江5个无居民海岛的植物资源现状进行详细踏勘,根据所获得的实地调研数据以及对文献资料的查阅,运用植物区系地理学,对研究地的种子植物区系物种组成、科-属的分布区类型、分布生境类型等进行统计整理,与不同地区无居民海岛种子植物属的相似性系数和属的地理成分进行对比,并探讨5个无居民海岛之间维管束植物物种相似度以及与岛屿空间特征参数的关系。结果表明:(1)连江5个无居民海岛共有野生种子植物190种,隶属于64科165属;该种子植物区系的数量优势科为菊科、禾本科,大科、较大科、属种优势明显,寡种科、仅含1种的科数量多。生活型以草本(55.94%)和灌木(23.27%)居多,乔木和藤本数量不占优势,分别仅占13.86%和6.93%。(2)区系组成繁杂多样,在科、属水平上均以热带分布类型为首要,分别为90.24%、68.03%,其中泛热带分布分别占科、属的75.62%、36.05%,科级的温带类型只有9.76%,属级占31.97%,热带类型科-属与温带类型科-属的R/T值分别为9.25和2.13,表明连江5个无居民海岛种子植物区系主体为热带、亚热带成分,与其亚热带地理特点相符,呈热带至亚热带过渡特征。(3)地缘关系上,将连江5个无居民海岛与中国从南往北4个不同地区无居民海岛种子植物区系对比,连江5个无居民海岛种子植物区系在属相似性上与纬度相近的平潭6个无居民海岛最相似,属相似性系数为71.32%。连江5个无居民海岛属的R/T值为2.13,低于厦门近岸海域无居民海岛(4.23)和平潭6个无居民海岛(2.58),高于浙江沿海5个无居民海岛(1.11)和渤海区9个无居民海岛(0.66),温带分布型所占比例随着纬度增大呈现逐渐递增的趋势,热带分布型占比在缩小,体现了海岛植物区系地理成分的纬向分异性,R/T值越大,热带性质越强。(4)物种相似性上,5个无居民海岛间植物物种相似度较低,岛屿空间特征参数的相关性分析表明,无居民海岛相似性受岛屿边缘效应和生境多样性二者的影响。总体上,连江5个无居民海岛种子植物区系植物种类多样,古老植物丰富,呈热带、亚热带过渡性质,与其泛北极植物区与古热带植物区过渡地带的地理特征相符。

某FAB厂房结构微振动有限元计算与分析

为研究电子厂房防微振结构设计方法,在对该厂区进行场地环境振动实测后,采用了有限元软件建模计算并分析了半导体厂房结构的微振动水平。结果发现:厂房二层各区域的振动预测均满足微振要求VC-B和VC-C标准;各测点的振动峰值主要集中在2 Hz、12.5 Hz、25 Hz三个频段附近。分析预测结果可为类似的项目提供经验并指导结构设计。

库布齐沙漠光伏电站气象特征观测及降尘微量元素分布规律

2023年3月对位于库布齐沙漠中的光伏电站开展环境和气象综合观测实验,分析光伏面板降尘中微量元素含量,定量阐述光伏电站对当地气候环境的影响,阐明降尘微量元素的分布规律.结果表明,上午电站内空气温度高于电站外,下午相反.下层平均气温站内为4.43℃,比站外降低了0.82℃.电站内底层空气湿度明显高于高层,最大差异达10%以上,并显著高于站外底层.电站内风速显著低于电站外,站内底层风速较站外降低了59.8%.光伏电站内降尘量为1.70 g/m^(2),比站外低170.27 g/m^(2),光伏电站防风固沙效果显著.不同类型光伏面板上降尘量不同,固定可调型光伏面板上降尘量为0.45 g/m^(2),比追踪型光伏面板降尘量低0.6 g/m^(2).光伏电站内降尘中元素Fe含量最高,其次是Mn、Mo.光伏电站场地中央w(V)、w(Cr)、w(Zn)、w(Ni)、w(Cu)、w(Pb)和w(As)分别为1.67×10^(-7)、1.19×10^(-7)、1.70×10^(-7)、1.70×10^(-8)、6.90×10^(-8)、2.20×10^(-8)和5.00×10^(-9),显著低于电站边缘和沙漠边缘,光伏电站有助于降低有毒重金属元素的富集.

蒜头果幼苗衰退过程中组织养分含量变化特征

在没有寄主植物存在的情况下,蒜头果幼苗长势随独立生长时间延长而逐渐衰退是一种普遍现象。为解析蒜头果幼苗衰退过程中组织养分含量变化和分布特征,该研究比较了独立生长半年、两年和三年的蒜头果植株各部分组织中N、P、K元素浓度变化,并用组织切片染色法定性评估了这些不同衰退程度幼苗的根和茎杆中淀粉分布和含量变化。结果表明:(1)蒜头果幼苗在衰退过程中,除侧根中K浓度逐渐升高外,其余器官中组织N、P、K浓度逐渐降低,叶片N/P比逐渐失衡,衰退程度不同的幼苗所受的养分胁迫类型存在差异,其中独立生长半年的蒜头果幼苗主要受N供应不足的限制(平均N/P比11.33),两年后转为P限制(平均N/P比17.81),三年后蒜头果幼苗叶片N/P比严重失衡(均值52.46),活力极低,不适合用于造林。(2)植株淀粉含量水平逐渐降低,独立生长三年后蒜头果幼苗植株中淀粉消耗殆尽。幼苗茎根交界处、根顶膨大处、主根及侧根的淀粉含量水平在不同衰退程度的幼苗间差异均较显著,表明淀粉含量水平可以作为评估幼苗活力的重要参考,其中侧根可以作为微创法检测幼苗活力的理想取样部位。鉴于独立生长的蒜头果幼苗活力逐渐衰退与组织养分含量降低有关,在蒜头果育苗过程中应合理补给矿质元素、配植优良寄主植物并尽早移栽,以免因幼苗活力衰退而导致造林成活率降低。该研究结果为寻找评估蒜头果幼苗活力的方法提供了理论参考和技术借鉴,并为育苗过程中合理施肥提供了科学指导。

专业认证下基于项目教学法的植物病理学研究方法课程教学体系构建

工程教育专业认证是国际通行的工程教育质量保证制度,能够为学生毕业后职业准备的范围和质量提供保证。植物病理学研究方法是东北农业大学植物保护专业认证的核心建设课程,也是具有较强应用性和实践性的实验课,是学生能够进入农业科研领域和解决农业生产实际问题的基础工具。本课程依据专业认证三大核心理念,采用项目教学法并将思政元素融入植物病理学研究方法的教学体系,力求实现“教书”“育人”“创新能力”和“职业能力”的协同一体化,进而促进学生全面发展。

丽水市种子植物区系分析

分析丽水市各县(市、区)植物区系特征及开展区系分区,可更深入地掌握该市植物区系性质与特点,为植物资源保护与开发利用提供科学依据。本文通过野外调查(2018—2019年)和资料收集(2017—2019年),对丽水市各县(市、区)植物名录进行了梳理。结果表明,丽水市有野生种子植物160科921属2785种,以庆元县物种数最多,有155科784属2069种,科、属、种数分别占丽水市种子植物科、属、种总数的96.88%、85.12%和74.29%,龙泉市次之。地理成分上,科级层面热带分布科数与温带分布科数的比值为2.00,各县(市、区)热带分布科数与温带分布科数的比值在1.84~2.09之间,表明科级以热带起源为主;属级层面热带分布属数与温带分布属数的比值为0.83,各县(市、区)分布属数与温带分布属数的比值在0.75~0.89之间,表明属级以温带起源略占优势。植物区系分区上,大体以云和、松阳为界,可以分为西部中山区(Ⅰ区)和东部低山区(Ⅱ区)。其中,Ⅰ区可划分为庆元—龙泉亚区、遂昌亚区和景宁亚区3个亚区;Ⅱ区可分为云和—青田—缙云亚区、松阳亚区和莲都亚区3个亚区,各亚区之间相互联系,又各有特色,体现了丽水种子植物区系的复杂性和多样性。龙泉—庆元亚区和景宁亚区物种多样性指数最高,是今后深入挖掘特色物种的重点区域。

思政元素融入园艺植物保护课程教学的改革与实践

园艺植物保护是高职园艺技术专业的一门专业核心课程,主要涉及常见虫害的形态特征、发生规律,以及常见病害的症状、发病规律及综合防治等内容,其知识结构在相关专业课程体系中具有非常重要的支撑作用。针对目前该课程在教学中存在的问题和面临的困境,结合岗位能力需求,分析园艺植物保护课程的知识结构与培养目标的联系,挖掘课程内的思政元素,探讨明确课程思政目标、修订教学大纲、完善课程思政设计和创新课程考核体系等方面,以期通过课程思政的建设与实践,达到立德树人的目标。