镉及镉锌交互作用的植物效应

镉是植物生长的非必需元素，而锌是植物生长必需的微量元素。虽然它们对植物的作用截然相反，但它们之间存在着复杂的交互影响关系。总结了镉对植物的生物效应，镉锌交互作用对植物的影响，包括：对元素的吸收积累，酶活性，细胞分裂等，论述了其主要影响因素，并探讨了Cd—Zn拮抗和Cd—Zn协同作用的可能机理。     

镉对植物根系的毒害作用

镉是一种毒性很强的重金属,可严重影响植物的生长。当镉对植物产生毒害作用时,首先表现在根系的形态和生理功能改变上。综述了镉胁迫下植物根系的形态学变化及生理生化改变,以及镉在植物体内的代谢过程,初步探讨了根际土壤对植物吸收镉的影响,并简单介绍了目前测定根系指标的常用方法。     

镉与植物活性氧代谢

镉是毒性最强的重金属之一，对人体健康具有潜在危害。研究证实，镉影响植物活性氧代谢，进而导致植物生理功能紊乱。     

镉对植物光合作用的影响

从光合速率、叶绿体及叶绿素、光化学反应、电子传递、光合作用中CO2同化等方面概述了镉（Cd）对植物光合作用的影响，力图阐明Cd影响植物光合作用的生理机制。     

水稻镉(Cd)毒害及其防治研究进展

镉是一种毒性很强的重金属,可严重影响水稻正常生长,并引起稻米镉污染。从水稻对镉的吸收、转移和分布,镉毒害效应和机理,水稻对镉毒害的耐性机理等3个方面综述了水稻镉毒害及其防治研究进展,并介绍了目前防治水稻镉污染的主要方法。     

苎麻和土壤中镉的FAAS法测定及其在镉污染土壤改良利用中的应用

介绍了火焰原子吸收光谱法 (FAAS)测定矿区农田镉污染土壤、苎麻样品中镉的分析方法 ,讨论了在环境镉污染土地上种植苎麻等植物在污染土壤改良和利用中的作用。方法准确、简便、快速。测定镉的最低检测浓度为 0 0 0 9μg·mL- 1,相对标准偏差为 0 61 % ,回收率在 97%～1 0 2 %之间。应用于环境镉污染区苎麻、土壤样品的测定 ,获得满意结果     

镉从农业土壤向人类食物链的迁移

综述了镉在环境中的行为，在土壤－植物－人类系统中的迁移，由于粮食作物是镉进入人类食物链的主要来源，因此土壤污染的危害是全球性的，对决定农业系统中镉迁移动力学的关键过程、粮食作物中的镉含量、影响镉植物有效性的各类因子作了综述了讨论。     

镧对水培菜豆和玉米幼苗镉胁迫的缓解作用

以菜豆(Phaseolusvulgaris)、玉米(Zeamays)两种生活型植物幼苗为实验材料,以水培方法研究了镧对镉抑制两种作物生长与代谢的影响。结果表明,在30,300μmol·L-1镉剂量胁迫下,两种作物的生长受到严重抑制,主要表现为株高、主根长下降,叶面积锐减,叶、茎、根的鲜重、干重明显下降;生理生化特性的变化是叶绿素含量下降,质膜透性、MDA含量、过氧化氢酶和过氧化物酶活性均增加,且随镉处理时间的延长,伤害加重。叶面喷施10～20mg·L-1镧1次,对镉污染下的两种作物幼苗的生长与代谢有一定缓解效应,可减轻镉对幼苗的伤害程度。这与镧能提高两种作物植物叶绿素含量,降低细胞膜透性和MDA含量,维持过氧化氢酶和过氧化物酶活性等多重作用相关。     

成都市土壤-植物系统中镉的分布特征

对成都市蔬菜及根系土中镉含量数据进行了综合分析。结果发现,成都市土壤镉存在明显的区域分布规律;镉在莴笋体内主要分布在叶片部位;土壤和植物中镉的总量无显著相关关系,可为给城市的环境规划及治理提供科学依据。     

镉污染土壤的植物修复

Cd在土壤中有稳定、积累和不易消除的特点,且可通过食物链富集使人体产生慢性中毒。我国农村镉污染尤其严重。植物修复技术是优秀的土壤镉污染治理技术,近两年来成为研究热点。本文阐述了土壤镉污染植物修复技术的机理、具体做法和技术进展。     

砷对植物生长的影响及植物耐砷机理研究进展

砷污染问题是全球面临的重大环境污染问题之一。综述了不同浓度砷及不同形态砷对植物生长的影响，耐砷植物及植物耐砷机理，指出了今后研究的主攻方向。     

川芎栽培土壤中重金属镉的动态监测

目的：连续多年监测彭州敖平镇川芎药材栽培土壤中重金属镉的含量,分析其对川芎药材中镉含量的影响。方法根据前期研究结果选取敖平镇部分川芎种植地固定采集样品。按照国家标准方法,采取0～20 cm连续根系土柱和川芎药材。采用火焰法对抽样土壤及川芎药材中镉的含量进行检测分析。结果采样区域内土壤中镉含量均符合国家二级土壤环境质量标准;部分土壤中镉的含量呈明显增长趋势。结论川芎种植土壤中镉含量与环境有较高关联,水泥厂粉尘等污染源是土壤中镉含量增加的重要来源。     

Sequential extraction procedure for speciation of inorganic cadmium in emissions and working areas

A sequential extraction procedure for separating and concentrating soluble Cd(II) salts, CdO, Cd(0), CdS, CdSe and cadmium-aluminosilicates, has been developed for the cadmium speciation in samples such as particulate matter in emissions and working areas. The proposed procedure has been tested first on synthetic samples prepared in a laboratory with the different cadmium salts, then also in the presence of atmospherical particulate matter sampled in a laboratory of the Department of Analytical Chemistry, previously checked for the absence of cadmium. Finally the speciation was tested on particulate matter collected near the emission of a power plant fed by coal, after emission's treatment by electrostatic precipitator: matrix spiking and recovery analyses have been evaluated and the repeatability of the cadmium speciation was assessed by performing multiple analyses of the spiked samples. Quantitative determinations have been made by FAAS and GFAAS through the standard additions method.     

Urea Assisted Synthesis of Flower Like CuO Nanostructures and Their Chemical Sensing Application for the Determination of Cadmium Ions

The novel nanostructures of CuO with improved morphology are strongly required for the development of devices with enhanced performance. In this study flower like nanostructures of CuO are synthesized by hydrothermal method using urea as tuning material for the morphology of CuO during the growth process. Scanning electron microscopy (SEM) and X‐ray diffraction (XRD) techniques were used for the characterization of these nanostructures. The nanostructures are highly dense, uniform and well aligned on the gold coated glass substrate. Moreover, CuO nanostructures exhibited pure phase of CuO. These novel CuO nanostructures were potentially used for the construction of cadmium ion sensor by functionalizing with tetrathia‐12‐crown‐4 a selective cadmium ion ionophore. The proposed cadmium ion sensor has detected the wide range of cadmium ion concentrations from 1.0×10^?9–1.0×10^?1 M with a sensitivity of 29.3±0.3 mV/decade and also a fast response time of less than 10.0 s is demonstrated. CuO nanostructures based cadmium ion selective electrode has also shown excellent reproducibility, repeatability, selectivity, and stability. The sensor electrode was also used as indicator electrode for the confirmation of practical utility and the obtained result describes the good behavior of the sensor in the potentiometric titration for the determination of cadmium ions.     

Plant calorimetry. Part 2. Modeling the differences between apples and oranges

In a previous review we discussed calorimetric methods for the study of plant metabolism. Since that review, a number of papers describing calorimetric measurements examining plant growth, stress responses and effects of temperature have appeared. This recent work is reviewed here.

In addition to the experimental work, a mechanistic model linking respiration rates to growth has been published. This model is derived from both mass and enthalpy balance equations. It describes specific growth rate and substrate carbon conversion efficiency as functions of the metabolic heat rate, the rate of CO₂ production, the mean oxidation state of the substrate carbon produced by photosynthesis, and enthalpy changes for conversion of photosynthate to biomass and CO₂. Application of this model to understanding the basis for variation in growth rates among individual genotypes in plants is reviewed.

The effects of environment on the plant respiration-growth relation has been an important focus for plant calorimetry studies. Climatic temperature is one of the most important variables determining growth. Extremes of temperature determine limits of growth, and diurnal variation and mean temperature have a major influence on growth rate. Calorimetric measurements of respiratory rates as a function of temperature can be used to relate the temperature influence on respiratory metabolism to the temperature influence on growth rate. These studies have also discovered the existence of an isokinetic point within the range of normal growth temperatures. Studies of temperature dependence are reviewed and the results analyzed in terms of the recently published mechanistic model.     

Different growth response of Euglena gracilis to Hg, Cd, Cr and Ni compounds

The toxicity of inorganic mercury, nickel, chromium and cadmium on the unicellular photosynthetic flagellate Euglena gracilis, strain Z (E.g.) has been tested. Under the conditions used each metal impaired the growth rate of E.g., and had a very strong effect on cell motility. The degree of cytotoxicity and motility decreased from mercury iodide to cadmium chloride to cadmium nitrate to potassium dichromate to nickel sulfate. No mutagenic effects of the metals investigated have been observed. Adverse effects of metal compounds can be tested on the eukaryotic species of Euglena gracilis used as an intermediate model system between bacterial and animal model.     

Determination of mineral balances in sheep offered feed with added cadmium and zinc

The optimum conditions for microwave digestion of herbage and faeces to determine mineral concentrations were obtained by varying sample mass, reagent and heating programme, and it was confirmed that the resulting element concentrations were the same as for certified reference material. The effects of feeding cadmium to sheep at a level that is typical of polluted regions (1 mg/kg) for ten days were investigated, as well as the possible amelioration of cadmium effects by adding 30 mg/kg Zn to the diet. Cadmium in the feed increased the cadmium balance and produced several mineral disturbances, in particular a reduction in sodium balance which is typical of renal tubular disorders. Including zinc in the diet as well as cadmium reduced the cadmium balance to a level similar to that of sheep that did not receive cadmium or zinc, which suggests that the zinc status is critical in determining whether cadmium in feed increases the cadmium balance in sheep.     

The structure and photoelectrochemical properties of cadmium selenide thin films made by tarnishing reactions

Thin film photoelectrodes of cadmium selenide have been made by using the tarnishing reaction between cadmium metal and selenium vapour. These electrodes have interesting photoelectrochemical properties as seen in photocurrent spectra, impedance measurements etc. They also make quite efficient photoanodes in a photoelectrochemical solar cell. Their structure and growth has been studied by various techniques including spectroellipsometry.