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1.
《国际贸易实务》是一门专门研究国际间商品交换具体过程的学科,是一门具有涉外活动特点的实践性很强的综合性应用科学。本文对《国际贸易实务》的教学内容进行了一些探讨,主要包括:正确处理《国际贸易实务》与其它相关课程之间的关系;按照业务流程调整教学内容的结构安排;合理安排理论教学与实践教学的比例;不断更新教学内容;突出教学重点与难点;树立风险防范意识,有效防范风险。  相似文献   

2.
农业转基因生物安全管理及我国的策略选择   总被引:7,自引:0,他引:7  
农业转基因技术的飞速发展,在展示了为人类可持续发展提供良好前景的同时,也日益显现出对生态环境和人类健康所构成的潜在风险与威胁。本文介绍了我国的《农业转基因生物安全管理条例》及其主要内容,并在分析了国外农业转基因生物安全管理的现状后,提出了我国的策略选择,即:尽快完善我国农业转基因生物安全管理的法规体系;保证《农业转基因生物安全管理条例》的顺利实施;加强农业转基因生物安全性的研究;加强转基因生物与国际贸易关系的政策研究;在国际条约的制订及谈判中坚持发展中国家的立场。  相似文献   

3.
时代发展对《工程制图》这门课程的教学也有了不同的要求。本文从传统的《工程制图》课程存在的问题着手,基于创新设计的要求,从教学内容、教学手段和实践路径等方面初步探讨了本课程教学所应进行的改革,以取得更好的教学效果。  相似文献   

4.
摘要:清洁生产实务是环保类专业学生的一门重要专业课程,作者探讨了在课程教学过程中的问题和对清洁生产实务课程进行的教学改革,取得了良好效果。  相似文献   

5.
欧洲的生态包装运动及其对我国的启示   总被引:3,自引:0,他引:3  
周钟 《环境保护》2001,(9):38-39
本文概述了生态包装及生态包装运动的兴起;并从理论层面和实践层面两个角度分别剖析了生态包装对国际贸易的影响;继而提出了史国面对生态包装运动的影响应采取的对策建议,以及对外经贸实务中应注意的生态包装问题。  相似文献   

6.
胡爱彬 《环境工程》2023,(1):318-319
<正>随着社会的不断发展,如何平衡环境保护与社会发展之间的关系成为当务之急。化学学科与环境问题息息相关,环境教育是环境保护中的前置环节,因此要强化二者融合,加强在化学教学中的环境教育。由方伟达编写、社会科学文献出版社出版的《环境教育:理论、实务与案例》一书,揭示环境教育的本质,具体阐述环境保护素养,可为高中化学教学融入环境教育提供理论参考。  相似文献   

7.
地方传真     
《环境工作通讯》2012,(1):115-117
《浙江省环境保护“十二五”规划》发布 浙江省人民政府日前印发了《浙江省环境保护“十二五”规划》。《规划》提出,到2015年,全省主要污染物排放总量显著减少,环境质量明显改善,环境安全保障体系基本形成,生态文明水平明显提高。《规划》围绕减少污染物排放、改善环境质量、防范环境风险、加强环境保护与“转方式调结构、惠民生促和谐”有机结合,提出了持续深化污染减排、着力改善环境质量、严格防范环境风险、全面加强生态建设和保护、健全生态安全保障体系5个方面的重点任务,涵盖了新阶段环境保护工作的重点领域。《规划》明确,“十二五”期间,浙江省将实施主要污染物减排、清洁水源、清洁空气、清洁土壤、重点领域环境风险防范、核与辐射环境保护、生态环境保护与建设、环境安全保障能力建设等八大重点工程,并从体制机制和制度安排等方面设定了相应的政策措施。  相似文献   

8.
《环境科学概论》作为自然地理与资源环境专业的一门专业基础课,具有明显的导引课程特点,知识覆盖面广,涉及学科领域多,教学难度大,对于培养学生的专业精神,培养学生的环境意识和科学素养,激发学生的专业兴趣均有重要的地位.结合西安科技大学自然地理与资源环境专业课程定位与目标、教学内容革新和教学方法革新等方面,针对《环境科学概论》的课程教学改革进行了探讨,提出了培养技术型和创新型的复合型人才培养目标模式与定位.  相似文献   

9.
《钳工工艺学》是一门有很强实践性的专业基础课,同时也涵盖了许多抽象的概念。技校学生由于基础差、底子薄,对学习缺乏兴趣。因此,教师不能只把重点放在知识的传授上,而是要把教学内容与日常生活中常见事例联系起来,挖掘各种趣味性因素,这样一来,可以调动学生的主动性,吸引学生的好奇心,激发学生的学习兴趣。通过在日常教学过程中的探索,我总结了自己的经验,归纳出了以下几个培养学生对这门课程的兴趣的方法。  相似文献   

10.
《环境保护》2005,(7):8-8
《关于在国际贸易中对某些危险化学品和农药采用事先知情同意程序的鹿特丹公约》(简称《鹿特丹公约》)6月20日正式对我国生效。该公约的实施可以有效限制或禁止某些对我国生态环境和人民身体健康危害严重的化学品进入我国.还能规范化学品进出口秩序。降低健康和环境风险,是我国化学品环境管理的良好契机。  相似文献   

11.
Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis (DGGE) and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity (both in gene richness and diversity index values) and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor (50 mg/kg) recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos (150 mg/kg) caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos (250 mg/kg) produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes (bands) responded differently to the impact of agrochemicals: four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.  相似文献   

12.
The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.  相似文献   

13.
Sorption of chlorotoluron in ammonium sulfate, urea and atrazine multi-solutes system was investigated by batch experiments. The results showed application of nitrogen fertilizers to the soil could affect the behavior of chlorotoluron. At the same concentration of N, sorption of chlorotoluron decreased as the concentration of atrazine increased on the day 0 and 6 in soil, respectively. The sorption of chlorotoluron increased from 0 to 6 d when soils were preincubated with deionized water, ammonium sulfate and urea solution for 6 d. That indicated incubation time was one of the most important factors for the sorption of chlorotoluron in nitrogen fertilizers treatments. The individual sorption isotherms of chlorotoluron in rubbery polymer and silica were strictly linear in single solute system, but there were competition sorption between pesticides or between pesticides and nitrogen fertilizers. That indicated the sorption taken place by concurrent solid-phase dissolution mechanism and sorption on the interface of water-organic matter or water-mineral matter.  相似文献   

14.
Several main metabolites of benzo[a]pyrene (BaP) formed by Penicillium chrysogenum, Benzo[a]pyrene-1,6-quinone (BP 1,6- quinone), trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene (BP 7,8-diol), 3-hydroxybenzo[a]pyrene (3-OHBP), were identified by high-performance liquid chromatography (HPLC). The three metabolites were liable to be accumulated and were hardly further metabolized because of their toxicity to microorganisms. However, their further degradation was essential for the complete degradation of BaP. To enhance their degradation, two methods, degradation by coupling Penicillium chrysogenum with KMnO4 and degradation only by Penicillium chrysogenum, were compared; Meanwhile, the parameters of degradation in the superior method were optimized. The results showed that (1) the method of coupling Penicillium chrysogenum with KMnO4 was better and was the first method to be used in the degradation of BaP and its metabolites; (2) the metabolite, BP 1,6-quinone was the most liable to be accumulated in pure cultures; (3) the effect of degradation was the best when the concentration of KMnO4 in the cultures was 0.01% (w/v), concentration of the three compounds was 5 mg/L and pH was 6.2. Based on the experimental results, a novel concept with regard to the bioremediation of BaP-contaminated environment was discussed, considering the influence on environmental toxicity of the accumulated metabolites.  相似文献   

15.
In this study an effort has been made to use plant polyphenol oxidases; potato (Solanum tuberosum) and brinjal (Solanum melongena), for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.  相似文献   

16.
RemovalofheavymetalsfromsewagesludgebylowcostingchemicalmethodandrecyclinginagricultureWuQitang,NyirandegePascasie,MoCehuiF...  相似文献   

17.
A study was conducted to compare the diversity of 2-, 3-, and 4-chlorobenzoate degraders in two pristine soils and one contaminated sewage sludge. These samples contained strikingly different populations of mono-chlorobenzoate degraders. Although fewer cultures were isolated in the uncontaminated soils than contaminated one, the ability of microbial populations to mineralize chlorobenzoate was widespread. The 3- and 4-chlorobenzoate degraders were more diverse than the 2-chlorobenzoate degraders. One of the strains isolated from the sewage sludge was obtained. Based on its phenotype, chemotaxonomic properties and 16S rRNA gene, the organism S-7 was classified as Rhodococcus erythropolis. The strain can grow at temperature from 4 to 37℃. It can utilize several (halo)aromatic compounds. Moreover, strain S-7 can grow and use 3-chlorobenzoate as sole carbon source in a temperatures range of 10-30℃ with stoichiometric release of chloride ions. The psychrotolerant ability was significant for bioremediation in low temperature regions. Catechol and chlorocatechol 1,2-dioxygenase activities were present in cell free extracts of the strain, but no (chloro)catechol 2,3- dioxygenase activities was detected. Spectral conversion assays with extracts from R. erythropolis S-7 showed accumulation of a compound with a similar UV spectrum as chloro-cis,cis-muconate from 3-chlorobenzoate. On the basis of these results, we proposed that S-7 degraded 3-chlorobenzoate through the modified ortho-cleave pathway.  相似文献   

18.
Single and joint effects of pesticides and mercury on soil urease   总被引:3,自引:3,他引:3  
The influence of two pesticides including chlorimuron-ethyl and furadan and mercury (Hg) on urease activity in 4 soils (meadow burozem and phaeozem) was investigated. The soils were exposed to various concentrations of the two pesticides and Hg individually and simultaneously. Results showed that there was a close relationship between urease activity and organic matter content in soil. Chlorimuron-ethyl and furadan could both activate urease in the 4 soils. The maximum increment of urease activity by chlorimuronethyl was up to 14%-18%. There was almost an equal increase (up to 13%-21%) in the urease activity by furadan. On the contrary, Hg markedly inhibited soil urease activity. A logarithmic equation was used to describe the relationship (P〈0.05) between the concentration of Hg and the activity of soil urease in the 4 tested soils. Semi-effect dose (ED50) values by the stress of Hg based on the inhibition of soil urease in the 4 soils were 88, 5.5, 24 and 20 mg/kg, respectively, according to the calculation of the corresponding equations. The interactive effect of chlorimuron-ethyl or furadan with metal Hg on soil urease was mainly synergic at the highest tested concentrations.  相似文献   

19.
A field study was conducted in the Taihu Lake region, China in 2004 to reveal the organochlorine pesticide concentrations in soils after the ban of these substances in the year 1983. Thirteen organochlorine pesticides (OCPs) were analyzed in soils from paddy field, tree land and fallow land. Total organochlorine pesticide residues were higher in agricultural soils than in uncultivated fallow land soils. Among all the pesticides, ΣDDX (DDD, DDE and DDT) had the highest concentration for all the soil samples, ranging from 3.10 ng/g to 166.55 ng/g with a mean value of 57.04 ng/g and followed by ΣHCH, ranging from 0.73 ng/g to 60.97 ng/g with a mean value of 24.06 ng/g. Dieldrin, endrin, HCB and α-endosulfan were also found in soils with less than 15 ng/g. Ratios of p,p'-(DDD DDE)/DDT in soils under three land usages were: paddy field > tree land > fallow land, indicating that land usage inlfuenced the degradation of DDT in soils. Ratios of p,p'-(DDD DDE)/DDT >1, showing aged residues of DDTs in soils of the Taihu Lake region. The results were discussed with data from a former study that showed very low actual concentrations of HCH and DDT in soils in the Taihu Lake region, but according to the chemical half-lives and their concentrations in soils in 1980s, the concentration of DDT in soils seemed to be underestimated. In any case our data show that the ban on the use of HCH and DDT resulted in a tremendous reduction of these pesticide residues in soils, but there are still high amounts of pesticide residues in soils, which need more remediation processes.  相似文献   

20.
Common silver barb,Puntius gonionotus,exposed to the nominal concentration of 0.06 mg/L Cd for 60 d,were assessed for histopathological alterations(gills,liver and kidney),metal accumulation,and metallothionein(MT)mRNA expression.Fish exhibited pathological symptoms such as hypertrophy and hyperplasia of primary and secondary gill lamellae,vacuolization in hepatocytes,and prominent tubular and glomerular damage in the kidney.In addition,kidney accumulated the highest content of cadmium,more than gills and liver.Expression of MT mRNA was increased in both liver and kidney of treated fish.Hepatic MT levels remained high after fish were removed to Cd-free water.In contrast,MT expression in kidney was peaked after 28 d of treatment and drastically dropped when fish were removed to Cd-free water.The high concentrations of Cd in hepatic tissues indicated an accumulation site or permanent damage on this tissue.  相似文献   

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