首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
黎子进 《广东化工》2010,37(6):87-89
化学危险品是具有爆炸、易燃、毒害、感染、腐蚀、放射性等危险特性,在运输、储存、生产、经营、使用和处置中,容易造成人身伤亡、财产损毁或环境污染而需要特别防护的物品。文章介绍了易燃固体、自燃物品及遇水放出易燃气体的物质、易燃液体、危险气体、爆炸品、毒性物质和感染性物质、氧化性物质和有机过氧化物六类化学危险品的基本特性,说明了其火灾预防措施,并概述了它们在发生灾害事故时的处置措施或灭火方法。  相似文献   

2.
《Ceramics International》2023,49(10):15874-15883
The standard approach towards synthesizing nanomaterials exercising chemical or physical techniques generally costs more and necessitates using toxic chemicals, which negatively affect the environment. For the first time, an investigation of a basic green synthesis approach for Phyto fabrication of Pd/TiO@BC nanocomposite via biomass of rice husk (Oryza sativa L) is conducted to sustain the green chemistry for synthesis of less toxic chemicals. XRD analysis revealed that the structure of Phyto synthesized Pd/TiO@BC is crystalline, while UV, FTIR, SEM and EDX analyses marked the victorious nanocomposite biosynthesis. We have investigated the electrocatalytic and biomedical applications of the novel nanocomposite Pd/TiO@BC at different environmental conditions. Testing the potential electrochemical properties of Pd/TiO@BC to eliminate the Congo red (CR) dye from wastewater marked its high removal efficiency, which attained 90% owing to the higher electron efficiency. Its sensitivity for CR was also examined, and acceptable degradation activity was observed. These Pd/TiO@BC proved to be beneficial in various fields, including electrochemistry, catalysis sensors, wastewater treatment, and nano-devices, and in the transformation of hazardous particles into less harmful substances. Its great potential for use as a supercapacitor is promised by its feature, including durability and compact stability. Significant guidelines could be extracted from the results, which are helpful in material size, synthesis, selection, and configuration design for various energy storage gadgets. The synthesis of high performance and economical materials through green chemistry is a novel approach towards effective energy storage and alteration procedure operation.  相似文献   

3.
Phase change materials (PCMs) are substances capable of absorbing and releasing large amounts of thermal energy (heat or cold) as latent heat at constant temperature as they undergo a change in state of matter (phase transition), commonly, between solid and liquid phases. Since the late 1940s, researchers have recognized the potential for phase change materials to play an essential part in energy storage systems and the search for suitable substances has received increasing interest. Currently, the global PCM market is estimated to grow from $ 460 million in 2013 to approximately $ 1.15 billion by 2018. Fats, oils, and their derivatives are diverse in their structures and among the few renewable feedstocks available that have melting and enthalpy profiles among other properties comparable to those of commercial paraffin waxes currently used in PCM applications. This has led to the investigation of triglycerides, fatty acids, esters, alcohols, and other lipid‐based derivatives as potential PCMs and much research examining lipid‐based materials as PCMs has been published. This article gives a brief overview of phase change materials, highlights the various types of lipid substances examined for PCM applications, and suggests potential future areas of study.  相似文献   

4.
核电厂的运行和检修过程用到多种化学品,其中一部分属于危险化学品. 核电厂中,危险化学品安全与核安全不直接相关,但其危害可能会与核安全叠加,从而将危害放大,因此核电厂危险化学品的设计和管理非常重要. 以二代改进型的M310压水堆核电厂为例,结合多个机组的设计实践,对核电厂中的危险化学品进行分析,并对主要危险化学品贮存设施的设计和管理进行论述. 经辨识,核电厂贮存使用的危险化学品不属于重大危险源;贮存设施设计方案严格按照标准规范执行,结合核电厂的特点设计足够的安全措施,措施完备并满足危险化学品日益严格的监管要求,保证了核电厂内的危险化学品的安全.  相似文献   

5.
There has been growing concern about man-made and naturally occurring chemicals in the environment in recent years. These chemicals interfere with the hormone (or endocrine) system, suggesting far-reaching effects on reproduction and development in current and future man and wildlife generations. Recent research has highlighted the existence of these substances in sewage and industrial effluents and their potential for recycling back into the environment, including drinking water, through point and non-point sources. 17β-Oestradiol (E2) and 17α-ethinyl oestradiol (EE2) are amongst the compounds of concern since they were found to cause adverse effects to fish even at low concentration levels.In this work, the adsorption of E2 and EE2 onto several granular activated carbons and Macronet polymers was investigated by batch experiments after a low level detection system was developed using Gas Chromatography Mass Spectrometry (GC/MS). Equilibrium experiments were carried out for all adsorbents to quantify the sorption capacity for E2 and EE2 and the data were correlated using conventional theoretical treatments. For better assessment of the sorbents, their physical properties including surface area, average pore diameter and micropore volume and chemical structure were characterised by N2 adsorption experiments. Further characterisation was performed with scanning electron microscopy (SEM), FTIR spectroscopy, sodium capacity determination, pH titration, development of proton-binding curves and zeta potential measurements. Kinetic experiments were performed at different size ranges of adsorbents and the results were analysed by applying a particle diffusion model. This study demonstrates the potential of these adsorbents for the removal of endocrine-disrupting compounds from aqueous solution.  相似文献   

6.
Hydrotalcite-like anionic clays (HTs; or layered double hydroxides, LDHs) can be used as precursors to mixed oxides, but their catalytic potential reaches much further. This review demonstrates that HTs can be successfully applied in a broad spectrum of organic reactions, with advantages such as improved activity, selectivity, metal dispersion, less waste production, and an improved recuperation of immobilized catalysts. HTs can be used in the as-synthesized form or after different pretreatments. The HT as such is a solid base or, depending on the elemental composition of its octahedral layers, may have redox properties. Specific metals can be incorporated either as a cation in the octahedral layer or as an anion via exchange. The anion-exchange strategy is especially successful in the context of heterogenizing homogeneous catalysts. A particular advantage for base catalysis is that the number and strength of the basic sites can be tuned precisely to a specific reaction. HTs are excellent materials to design bifunctional redox-base catalysts or to control the acid-base properties around a heterogenized metal complex. Potential applications of HTs range from the production of large-scale basic chemicals to the synthesis of small-scale specialty chemicals.  相似文献   

7.
《Catalysis Reviews》2013,55(4):443-488
Hydrotalcite-like anionic clays (HTs; or layered double hydroxides, LDHs) can be used as precursors to mixed oxides, but their catalytic potential reaches much further. This review demonstrates that HTs can be successfully applied in a broad spectrum of organic reactions, with advantages such as improved activity, selectivity, metal dispersion, less waste production, and an improved recuperation of immobilized catalysts. HTs can be used in the as-synthesized form or after different pretreatments. The HT as such is a solid base or, depending on the elemental composition of its octahedral layers, may have redox properties. Specific metals can be incorporated either as a cation in the octahedral layer or as an anion via exchange. The anion-exchange strategy is especially successful in the context of heterogenizing homogeneous catalysts. A particular advantage for base catalysis is that the number and strength of the basic sites can be tuned precisely to a specific reaction. HTs are excellent materials to design bifunctional redox-base catalysts or to control the acid–base properties around a heterogenized metal complex. Potential applications of HTs range from the production of large-scale basic chemicals to the synthesis of small-scale specialty chemicals.  相似文献   

8.
姬彩云 《云南化工》2018,(3):255-256
高校化学实验室中有大量危险化学品,化学实验用品具有易燃易爆特点,非常容易引发安全事故。在日常工作当中,危险化学品的储存、管理、使用都存在一定安全隐患,化学实验室是重点安全管制区域,加强化学实验室安全储存是实验室管理的关键。  相似文献   

9.
采用分析色谱技术,定量分析了飞天茅台、五粮液、枝江、白云边、山西汾酒、牛栏山二锅头及桂林三花酒等5大类7种不同香型的中国白酒。将其微量化学物质按国家卫生标准、体现白酒普通香味的微量化学物质以及具有特征香味的微量化学物质分为三大类,并按其含量和一定顺序用柱状图进行表达,从而得到其微量风味化学物质指纹图谱。尝试建立一种利用白酒微量化学物质指纹图谱鉴别白酒品质和香型的简易方法。  相似文献   

10.
Nanoparticles can experience numerous impacts during storage or after intravenous administration resulting in disassembly and/or drug leakage and affecting their efficiency as drug delivery systems. In this study, this crucial issue was addressed by investigating the stability of amphiphilic poly‐N‐vinylpyrrolidone derivative nanocarriers in blood serum, against destabilizing agents and during long‐term storage. All amphiphilic poly‐N‐vinylpyrrolidone derivative nanoparticles prepared in this study were found to possess sizes less than 150 nm, narrow size distribution, spherical morphology, and a slightly negative surface charge. These nanoparticles could efficiently entrap hydrophobic substances (pyrene and curcumin) while retaining excellent compatibility with red blood cells. Moreover, our studies demonstrate the stability of the nanoparticles during long‐term storage and upon dilution with body liquids enhancing their potential as stable in vivo carriers, which is critically important for intravenous drug delivery applications. All properties were found to strongly depend on the ratio between the hydrophobic and the hydrophilic moiety of the polymers under study. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45637.  相似文献   

11.
A number of well known polychlorinated chemicals are toxicologically and environmentally unsafe. Because of their persistence they are in the focus of public discussions against chlorine chemistry. However, chlorinated organic chemicals in the molecular weight range between 200 and 600 constitute an important and indispensable segment in the arsenal of existing biologically active chemicals used as pharmaceuticals or crop protection agents. Over the course of time it has been found empirically that the introduction of a chlorine atom into one or more specific positions of a biologically active molecule may substantially improve the intrinsic biological activity. In some cases the presence of a chlorine atom is even crucial for significant activity of a compound derived from nature or chemical synthesis like in the diverse compounds 1 to 12 and 23 to 30 . But in other cases chlorination diminishes or abolishes biological activity as shown for the chlordane homologues 139 to 143 . Thus a chlorine atom, like any other substituent, is a modulator of activity as represented in the many examples 31 to 124 . Almost all non-reactive chlorinated chemicals and chlorine-free chemicals are devoid of any biological activity at the highest concentration typically used in primary screening tests for discovery of useful biological properties. The influence of a substituent such as chlorine on the biological activity of a potential drug or crop protection agent still has to be established empirically in biological experiments designed to detect desired activity or toxicological properties. Sometimes chlorine does prove to be the optimum for improvement of activity. Long-term rigorous investigations of several hundred chlorinated compounds, registered by the authorities as pharmaceutical drugs or crop protection agents, show that the generalisation (“all chlorinated chemicals as a rule are dangerous”), deduced from the negative toxicological properties of a hundred chlorinated and reactive compounds of low molecular weight that are relevant in terms of safe working conditions in the chemical industry and for ecological safety, is not justified. Chlorinated compounds are not generally toxic or dangerous. Highly reactive chemicals or polychlorinated compounds can not be compared with regard to toxicological properties with unreactive compounds having a low degree of chlorination. The chlorine atom, as one of many possible substituents used in synthetic organic chemistry, will remain in the future one of the important tools for probing structure–activity relationships in life science research and as a molecular component in commercialised compounds, in order to provide safer, more selective and more environmentally compatible products with higher activity for medicine and agriculture.  相似文献   

12.
We present a new tool for hepatocarcinogenicity evaluation of drug candidates in rodents. ToxDBScan is a web tool offering quick and easy similarity screening of new drug candidates against two large-scale public databases, which contain expression profiles for substances with known carcinogenic profiles: TG-GATEs and DrugMatrix. ToxDBScan uses a set similarity score that computes the putative similarity based on similar expression of genes to identify chemicals with similar genotoxic and hepatocarcinogenic potential. We propose using a discretized representation of expression profiles, which use only information on up- or down-regulation of genes as relevant features. Therefore, only the deregulated genes are required as input. ToxDBScan provides an extensive report on similar compounds, which includes additional information on compounds, differential genes and pathway enrichments. We evaluated ToxDBScan with expression data from 15 chemicals with known hepatocarcinogenic potential and observed a sensitivity of 88%. Based on the identified chemicals, we achieved perfect classification of the independent test set. ToxDBScan is publicly available from the ZBIT Bioinformatics Toolbox.  相似文献   

13.
Carboxymethyl cellulose salt as a model compound was treated hydrothermally to understand the degradation and formation of several chemicals (furfural, 5‐(hydroxymethyl)‐furancarboxaldehyde, and benzene derivatives) that might be interesting as platform chemicals or fuels. To realize a manageable control, closed quartz capillaries were chosen as reactor. Experiments were conducted at temperatures from 250 (subcritical water) to 450 °C (supercritical water) and reaction times from 1 to 60 min. By studying the gas chromatography‐mass spectrometry analysis results of the liquid products, their formation and degradation were detected. It was observed that certain substances only appear for several minutes and are then degraded, while for others the concentration increases at lower rate and keeps stable even for long reaction times. The formation of several benzoic structures from a non‐ring‐structured precursor showed that different reaction mechanisms are involved. Different reaction temperatures showed good correlation to the formation rate of several substances.  相似文献   

14.
Enzymic adaptations in leaf-feeding insects to host-plant allelochemicals   总被引:1,自引:0,他引:1  
Herbivorous insects have the capacity to develop behavioral, physiological, and biochemical resistance mechanisms in response to chemical selection pressures. Among natural insect-plant associations, there are several cases of target-site insensitivity to and enhanced metabolism of plant allelochemicals. There are also known instances of physiological defenses such as extra rapid excretion or storage of toxic compounds. Multiple defenses seem to be prevalent in natural insect-plant interactions that involve toxic compounds, possibly reflecting the long time these interactions have had to evolve compared to insect-synthetic insecticide interactions. Synthetic insecticides were introduced about 45 years ago. Until recently they have been used as single-active-component preparations. As such, they have been and are very effective in producing insect populations with enhanced detoxification ability and target-site insensitivity. Most insecticide-resistant insect populations have one major defense mechanism. This feature makes the synthetic insecticides very useful tools for studies of insect defenses against toxic chemicals. Information gained from studies with insecticides can shed light on the capabilities of insects to adapt to toxicants in their environment. In assessing the validity of work with synthetic insecticides for natural systems, the fundamental differences between these substances and allelochemicals, and in their presentation to the insects, must, however, be considered. The prevalence of multiple defenses and reliance on modified physiological processes in natural interactions may reflect different properties of the natural chemicals in being generally highly biodegradable and often less acutely toxic than synthetic insecticides. In many cases, the plant allelochemicals are presented to the insects as mixtures. It is, however, to be expected that pest insects will evolve effective multiple defenses against synthetic insecticides. About 20% of all resistant populations have already developed multiple defenses, in most cases combinations of enhanced metabolism and target-site insensitivity. This implies that current crop protection practices need to be modified to ensure the continued usefulness of synthetic insecticides. To achieve this, it is important to study intensively not only insect-insecticide interactions but also the interactions operating in natural insect-plant associations.  相似文献   

15.
内分泌干扰物是一类能够影响人类和动物生殖发育的化学物质.水环境中内分泌干扰物的存在对人类的身体健康存在潜在性危害.近年来,在多个污水处理厂的进水中均检测到了内分泌干扰物.生物处理是有效去除该种类物质的方法之一.分析和综述了内分泌干扰物生物去除方法的主要工艺、作用机理和影响因素,提出了目前存在的主要技术难点和未来研究发展...  相似文献   

16.
The growth in polymer-based innovative packaging technology has brought about a revolution in extending the shelf life of many food and aquatic products. One of the emerging areas in this field is polymer nanocomposite (PNC) technology, which involves the incorporation of various chemicals and nanoadditives into polymers to improve their inherent properties or to add required functionality. Because the nanoparticles may interact with food components during processing, storage, or distribution and may migrate into food, PNC-based packaging materials require awareness and understanding of their potential impact on human health and the environment. Interest in migration and cytotoxic analysis of PNC has gained considerable momentum in recent years. The focus of this article is on clay-containing PNCs because the global trend in PNCs shows that 50% of all nanofillers constitute nanoclays of either natural or synthetic origin. This article presents a summary of perspectives on international regulations on test parameters and migration of chemicals from materials that come into contact with food, followed by a critical review of (1) complaints concerning the polymers, compatibilizers, and adhesive tie layers used in polymeric packages, (2) migration of constituents from PNC-based films/articles, and (3) toxicity evaluation of nanoclays and migration of nanoclays from PNCs. Finally, we believe a review article of this nature will help academic and industrial researchers who want to bring advanced PNC-based products into the market for food packaging applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47214.  相似文献   

17.
危险化学品在储存和运输过程中具有较大的危险有害性,一旦发生事故,后果往往也相当严重。危险化学品的运输有公路运输、铁路运输、水上运输和管道运输等几种方式,分析了这几种运输方式以及仓储时存在的安全隐患,旨在引起业内人员对危化品储运安全的重视。  相似文献   

18.
一种精细化工新产品—过碳酰胺   总被引:6,自引:0,他引:6  
详细介绍了一种精细化工新产品──过碳酰胺的性质、加工及储存条件、分析检测方法、用途及使用方法等。  相似文献   

19.
The Ministry of the Environment in Korea supports investigation of various substances that are potential contaminants of the environment and could cause adverse effects on the environment and/or human health and to list Priority Substances (PSL). The present study for PSL is aimed at estimating the new PSL for industrial areas or assessing the risk of refining processes for selecting priority substances in order to obtain better criteria of quality data. The present study lists 81 major priority substances among 106 candidate substances and scores with weight factors to CHEMS-1 based on amounts of materials in circulation and emissions levels. Of the 81 chemicals, 80% are classified as carcinogens, potentially causing acute oral toxicity among those within the 1st grade of data quality criteria for materials. For data quality criteria of items, BOD or hydrolysis half-life is the lowest 40% and acute oral toxicity is the highest 90%.  相似文献   

20.
绿色化学及其技术在水处理的应用   总被引:13,自引:2,他引:11  
陆柱 《精细化工》2000,17(9):515-518
近年来绿色化学及其技术的应用已经成为环境保护和防止污染的重要方面。绿色化学可将污染控制在一定水平 ,即在化学品的制造和应用中降低或消除有毒有害物质。水处理缓蚀剂和阻垢剂作为一类化学品 ,如果在这些领域应用绿色化学技术 ,可以减少或消除许多有毒有害的化学品 ,并在此基础上开发新型的环境友好型的水处理药剂。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号