当前复混肥料产品标识标注存在的问题和建议

近年来 ,复混肥料产品标识混乱状况比较突出 ,胡乱标注标识误导农民消费 ,从而造成肥害事件时有发生。为此 ,提出必须采取切实措施 ,加强市场肥料监督管理和有关标准的宣贯力度 ,加快新标准研究制定步伐 ,同时引导肥料生产企业准确标注标识 ,并普及和提高农民科学施肥的技术和水平     

International fertilizer development center training and technical assistance activities: A review

The mission of the International Fertilizer Development Center (IFDC) is to assist developing countries in increasing food production through increased and more efficient use of fertilizers. To this end, IFDC has conducted training programs and implemented technical assistance activities designed to develop and transfer fertilizer technology appropriate to the needs of farmers in the tropics and subtropics. IFDC is committed to helping developing countries to strengthen all components of their fertilizer sector to ensure sustainable crop production through the efficient supply and use of fertilizer.     

国内堆垛机技术发展及应用

根据国内水平堆垛机的现状和发展要求,阐述了现有水平堆垛机存在的问题及解决方法.     

国外乳胶制品的开发与技术进展

<正>乳胶制品因具有超高弹性、触感性强、着戴性佳、矫形功能好、生物性能良好等优点,在工农业生产、医疗卫生、军工领域、文化体育、日常生活中都有着广泛的应用。较为常见的乳胶制品主要有乳胶手套、乳胶安全套、乳胶气球、乳胶胶管、乳胶指套、乳     

Nylons: A review of the literature on products of combustion and toxicity

The literature on polyamides was reviewed to determine the nature and extent of information available on these materials which are commonly used in consumer and industrial applications. This review was limited to aliphatic polyamides normally called nylon and excludes aromatic polyamides such as Nomex and bicomponent polymers consisting of nylon and other polymers. The review was further limited to those publications in English through June 1984. Typical pyrolysis products from a broad range of nylons do not appear to differ greatly. Many of the decomposition products detected in vacuum pyrolysis experiments appear as products of thermal degradation in inert and air atmospheres. In air, a general reduction in the quantities of heavier hydrocarbons is noted along with an increase in the production of CO, CO₂, H₂O, NH₃, HCN and NO_x. The toxicity of the thermal degradation products from various types of nylon has been evaluated by nine different protocols. Reported LC₅₀ values range from 10.8 m l^?1 to 61.9 mg l^?1. Dyes apparently do not affect the materials' combustion products toxicity but an increase in the amount of backcoating on a nylon fabric increases toxicity. Time to death measurements show that volatile products from nylons are less toxic than those from rayons or cotton, while the blending of wool with nylon greatly increases the toxicity of the thermal decomposition products. In general, however, the overall toxicity of the thermal degradation products from nylon do not appear to be greatly different than those from many other polymeric materials. Large-scale test results are ambiguous, and it is difficult to interpret the results in terms of a single component in a multicomponent system.     

Sugar-based surfactants for consumer products and technical applications

Sugar-based surfactants, such as sorbitan esters, sucrose esters, alkyl polyglycosides, and fatty acid glucamides gain increasing attention due to advantages with regard to performance, health of consumers, and environmental compatibility compared to some standard products. Sorbitan esters are well established products, which are mainly used as leather and textile auxiliaries or as emulsifiers for food at a volume of approx. 20,000 t/a. Sucrose esters are relatively hydrophobic products. The actual market size is estimated to be < 4,000 t/a – the main application being emulsifiers for food and cosmetics. Their use is still limited. Alkyl polyglycosides and fatty acid glucamides represent a perfect amphiphilic structure with excellent surface activity as well as solubility due to highly selective syntheses. For alkyl polyglycosides industrial processes have been developed in the past couple of years and a total capacity of ca. 80,000 t/a has been established. They are mainly used for cosmetic, manual dishwashing, and detergent applications. Fatty acid glucamides to date are exclusively used by one company in liquid and powdered detergents. The estimated production capacity is approx. 40,000 t/a. Comparable in their performance profile as co-surfactants, both products differ in their raw material base: whereas in the case of the fatty acid glucamides methylamine is incorporated in the product, alkyl polyglycosides are completely based on renewable resources. This, combined with very good performance and mildness, could be one reason why alkyl polyglycosides are the most successful sugar-based surfactants nowadays. Research to develop derivatives on this basis is still ongoing.     

Protein co-precipitates: A review of their preparation and functional properties

Advances in protein co-precipitation technology over the past two decades have made it possible to commercially produce different types of proteins from mixtures of raw materials. Incorporation of protein co-precipitates improves the functional (e.g. appearance, texture, and stability) and nutritional characteristics of many food products. Increasing world population, increasing demand for and cost of protein-rich foods, and the continuing need to improve the nutritional and functional properties of protein ingredients have contributed to greater research into blends or composites as food ingredients. Protein co-precipitates have a range of biological, physical, chemical, functional, sensory and nutritional properties giving the potential application as ingredients in the food industry, though relatively little published information is available on this subject. There is limited information about the use of protein co-precipitates by the food industry when developing products for different groups of potential consumers. The aim of this review is to evaluate the current status of protein co-precipitate research as a potential way of improving utilization of protein rich raw materials (e.g. dairy protein), oil seed meals (e.g. sesame, soybean, flaxseed and canola) and by-products (e.g. brewing yeast). By blending proteins from different sources, protein co-precipitates are a way of overcoming deficiencies in essential amino acid contents found in proteins from a single source, which giving ingredients with good functional properties and desirable sensory characteristics.     

A review of antioxidant analysis in food products

To permit proper usage of antioxidants by the food processor and permit control under applicable governmental regulations, it is necessary to have adequate analytical methods. Such methods should both positively identify and provide a quantitative assay for the additive. Due to the complex nature of foods, analysis of an antioxidant in the very small quantities used presents a very real problem. Solvent extraction and/or steam distillation techniques are employed to separate the antioxidants from the food. Ultraviolet spectra, gas chromatography and colorimetric techniques are used to identify and determine the quantity of each antioxidant present. Slight variations are necessary for each type of food.     

天然产物抗氧化活性的常见评价方法

天然产物抗氧化活性的评价是天然产物研究的重要组成部分,对其在日化领域的开发应用具有显著的指导意义。本文从实验原理、实验方法等方面对天然产物抗氧化活性的常见评价方法进行综述,详细介绍了化学分析法中的自由基(ABTS自由基阳离子、DPPH自由基、超氧自由基、羟自由基)清除实验、脂质过氧化抑制实验、还原能力测定及脂质氧化抑制等评价方法;描述了以生物细胞为模型的CAA抗氧评价方法;概述了在动物体内进行的抗氧化活性评价方法及指标,为相关领域中抗氧化天然产物的研究和开发提供实验理论基础。     

Combustion of large volumes of dispersed fuels and the evolution of their products in the free atmosphere

Conclusions The results of the experiments show the significant effect of the dimensions of the gas—drop system on the character of its combustion: in the range of clouds with a volume greater than 500 m³, it is possible to attain apparent flame velocities greater than 100 m/sec. Here, it was established that in large aerosol clouds of atomized hydrocarbon fuels with a similar disperse composition, the apparent velocity of the flame increases with an increase in the molecular weight of the fuel.Comparison of the dynamics of ascent of the resulting vortex ring with the calculated data in [17] shows that the behavior of the combustion products of dispersed fuels in the free atmosphere can be classified as a case of free upward convection from an impulsive point source. The relation H(t)(Q_it²)^1/4 for this case is equivalent to the relation for the ascent of the products of a powerful explosion [14].Odessa. Translated from Fizika Goreniya i Vzryva, Vol. 25, No. 3, pp. 21–28, May–June, 1989.     

Organoleptic and nutritional effects of phenolic compounds on oilseed protein products: A review

In many new oilseed protein sources, phenolic compounds are as important as unsaturated lipids, carbonyl compounds, and nonenzymatic browning in the development of adverse flavors and colors in food products. The free phenolic acids are of particular concern because of enzymatic oxidation too-quinones and subsequent binding to lysine and methionine in the proteins. Numerous free phenolic acids have been identified in all oilseed flours with syringic, ferulic and vanillic being the major components in cottonseed, peanut and soybean flours. Gossypol in cottonseed, chlorogenic acid in sunflower, and sinapine in rapeseed are microconstituent phenolics which cause unique problems in the utilization of these defatted flours and their protein isolates in food applications. The roles of bound phenolics and tannins in the binding of essential nutrients or altering chemical and functional properties require further investigation.     

Thermal conductivity of carbon nanotubes and their polymer nanocomposites: A review

Thermally conductive polymer composites offer new possibilities for replacing metal parts in several applications, including power electronics, electric motors and generators, heat exchangers, etc., thanks to the polymer advantages such as light weight, corrosion resistance and ease of processing. Current interest to improve the thermal conductivity of polymers is focused on the selective addition of nanofillers with high thermal conductivity. Unusually high thermal conductivity makes carbon nanotube (CNT) the best promising candidate material for thermally conductive composites. However, the thermal conductivities of polymer/CNT nanocomposites are relatively low compared with expectations from the intrinsic thermal conductivity of CNTs. The challenge primarily comes from the large interfacial thermal resistance between the CNT and the surrounding polymer matrix, which hinders the transfer of phonon dominating heat conduction in polymer and CNT.This article reviews the status of worldwide research in the thermal conductivity of CNTs and their polymer nanocomposites. The dependence of thermal conductivity of nanotubes on the atomic structure, the tube size, the morphology, the defect and the purification is reviewed. The roles of particle/polymer and particle/particle interfaces on the thermal conductivity of polymer/CNT nanocomposites are discussed in detail, as well as the relationship between the thermal conductivity and the micro- and nano-structure of the composites.     

Lipid oxidation in meat and meat products—A review

Lipid oxidation is a major cause of deterioration in the quality of meat and meat products. Oxidation can occur in either the stored triglycerides or the tissue phospholipids. Ferric heme pigments have been implicated as the major prooxidants in tissue lipid oxidation. Pigment and lipid oxidation are interrelated, and ferric hemes are believed to promote lipid oxidation. The resulting oxidation destroys the hemes. Nonheme iron and ascorbic acid may also function as prooxidants in meat. Sodium chloride accelerates oxidation of the triglycerides, although the mechanism of salt catalysis is not completely known. Cooked meat undergoes rapid deterioration due to tissue lipid oxidation. The meat pigment in the cured pink ferrous form does not promote the rapid oxidation undergone by cooked uncured meat. Refrigerated and frozen fresh meats are also susceptible to lipid oxidation. Protein denaturation and cross-linking may result from lipid oxidation in stored freeze-dried meat. With increased consumption of prepackaged raw meat and precooked convenience meat items, control of oxidation has become increasingly important. Antioxidants and chelating agents are the most effective inhibitors of lipid oxidation. One of 28 papers presented at the Symposium, “Metal-Catalyzed Lipid Oxidation,” ISF-AOCS World Congress, Chicago, September 1970.     

Environment-friendly paints: their technical (im)possibilities

In this paper technical (im)possibilities of environment-friendly paints are discussed from a paint developer's point of view. Special attention is paid to acrylic emulsion paints for wood protection. Important and interesting examples are given based on binder technology and paint formulations.     

Polystyrenes: A review of the literature on the products of thermal decomposition and toxicity

The current English literature through 1984 on the products of pyrolysis and combustion from polystyrenes and the toxicity of those products is reviewed. Among 57 compounds detected by chemical analyses of the thermal decomposition products produced under various atmospheric conditions (vacuum, inert and oxidative), the main volatile component is the styrene monomer, Evidence is provided that the mass fraction of styrene increases with furnace temperatures at least through 500°C. At 800°C and above, the concentration of styrene decreases. In oxidative atmospheres, carbon monoxide (CO), carbon dioxide (CO₂) and oxidative hydrocarbons are formed. The concentrations of CO and CO₂ are a function of temperature and combustion conditions, i.e. greater amounts are produced in the flaming than in the non-flaming mode. Eleven different test procedures were used to evaluate the toxicity of the pyrolysis and combustion atmospheres of polystyrenes. The more toxic environments produced under flaming conditions appear to be mainly attributed to CO and CO₂ but rather to some other toxicant, probably the styrene monomer. When compared with other common materials used in buildings and residences, polystyrenes, in general, are among the least toxic.     

Methods for the determination of conjugated dienes in petroleum products: A review

The present review surveys the existing methods of analysis for the determination of conjugated dienes in petroleum products, including both chemical and instrumental techniques. Several methods of quantifying the total conjugated dienes amount in complex hydrocarbon mixtures have already been reported. However, the identification of each conjugated diene has been proved to be a difficult task to be done although a detailed analysis will enable a good correlation with the gum formation and the catalyst poisoning. Here the scope and limitation of each method in relation of its applicability to specific petroleum products are fully discussed.     

Combustion-derived nanoparticles: A review of their toxicology following inhalation exposure

This review considers the molecular toxicology of combustion-derived nanoparticles (CDNP) following inhalation exposure. CDNP originate from a number of sources and in this review we consider diesel soot, welding fume, carbon black and coal fly ash. A substantial literature demonstrates that these pose a hazard to the lungs through their potential to cause oxidative stress, inflammation and cancer; they also have the potential to redistribute to other organs following pulmonary deposition. These different CDNP show considerable heterogeneity in composition and solubility, meaning that oxidative stress may originate from different components depending on the particle under consideration. Key CDNP-associated properties of large surface area and the presence of metals and organics all have the potential to produce oxidative stress. CDNP may also exert genotoxic effects, depending on their composition. CDNP and their components also have the potential to translocate to the brain and also the blood, and thereby reach other targets such as the cardiovascular system, spleen and liver. CDNP therefore can be seen as a group of particulate toxins unified by a common mechanism of injury and properties of translocation which have the potential to mediate a range of adverse effects in the lungs and other organs and warrant further research.