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121.
三氯化氮(NCl3)是液氯生产中的一种副产物,是生产和使用过程中能够引起爆炸危害的一种易爆物质.其安全监控与防治的重要,已被我国氯碱科技工作者认同而获得共识.尽管如此,我国氯碱工业生产中三氯化氮爆鸣、爆炸事故还在经常发生,安全隐患尚未得到彻底的解决,对生产设备造成了严重的破坏,并造成不同程度的人员伤亡和氯气泄漏事故,损失惨重,危害极大.因此就三氯化氮的性能、爆炸与危害,主要来源、预防措施与消除方法进行了较为详尽的阐述.  相似文献   
122.
我国健身器材质量和检验现状分析及其对策   总被引:1,自引:0,他引:1  
笔者从产品质量、检测体系和质检监管等方面系统地阐述了我国健身器材产业的现状 ;通过对国内外健身器材产业的比较和分析 ,指出了我国健身器材产业普遍存在技术含量低 ,质量不稳定 ,检测标准和设备欠缺 ,服务不完善等突出问题 ;同时还具体探讨了国内外健身器材的安全要求和使用性能在生化和环保两方面的不足 ;就上述种种问题提出了相应的发展对策 ,即遵循“以人为本 ,保障安全”的原则 ,积极发展现代化生产企业 ,前瞻性地开发高技术含量的安全型产品 ,健全符合国情实际的检测体系 ,从而全面提升我国健身器材的安全性能、服务水平和市场竞争力  相似文献   
123.
介绍了用通风机性能曲线测定可视化计算机程序的设计。该程序基于Windows环境,采用C Builder5.0开发,可以实现数据的自动保存、处理,及性能曲线、结果报表输出,同时具有可视化的人机界面。应用该程序可以使通风机性能曲线测定试验更加简便易行,还可以使试验结果更加精确。  相似文献   
124.
利用多年的环境监测数据,分析南昌市环境空气中主要污染物尘类、二氧化硫和氮氧化物产生的原因,并提出有效控制上述污染物的具体措施。  相似文献   
125.
Ammonia emissions from two contrasting seabird colonies in Scotland were measured, based on the determination of atmospheric concentrations downwind of the colonies. Atmospheric concentrations of ammonia (NH3) across the downwind plume were compared with the inverse application of a Gaussian dispersion model (ID) to calculate the modelled NH3 emission that would generate the measured cross-wind-integrated plume concentration. In parallel, a tracer gas (sulphur hexafluoride, SF6) was released from the colonies with air samples taken to allow determination of SF6 concentrations. On the basis of the known emission rate of SF6, the magnitude of ammonia emissions was estimated by the cross-wind-integrated tracer ratio (TR) of NH3/SF6 concentrations. Coupled with data on annual bird attendance, the measurements indicate annual emissions from the Isle of May and the Bass Rock of 18 and 132 tonnes NH3-N year–1, respectively. The measured NH3 emissions were compared with estimates of seabird nitrogen excretion to estimate the proportion of excreted N that is volatilised as NH3 (FNr). The emission estimates of the two methods compared favourably, giving 4 and 6 kg NH3-N h–1 (FNr = 15%) for the Isle of May for the ID and TR methods, respectively, and 21 and 25 kg NH3-N h–1 (FNr = 50%) for the Bass Rock for the ID and TR methods, respectively. The results provide the first measurement-based estimates to allow regional up scaling of ammonia emissions from seabirds.  相似文献   
126.
This paper provides the background to this special issue, outlining the extent to which the global atmospheric nitrogen cycle has been modified by human activity and outlining the range of effects. The global total emissions of reduced and oxidized nitrogen, amount to 124 Tg N, and exceed those from natural sources (34 Tg N) by almost a factor of four showing the extent to which anthropogenic activity has taken over the global N cycle. Of the 124 Tg N, 70 Tg N is emitted in the oxidized form, largely as NO and 70% of which results directly from anthropogenic activity. The remaining 54 Tg N is emitted as NH3, (66% anthropogenic). The enhanced nitrogen emissions are associated with a range of local, regional and global issues including, acidification, eutrophication, climate change, human health and tropospheric O3. The paper also places the Global Nitrogen Enrichment (GaNE) research programme in the UK in a wider perspective.  相似文献   
127.
The distribution and impacts of different nitrogen pollutants are inextricably linked. To understand the problem fully, the interactions between the different pollutants need to be taken into account. This is particularly important when it comes to abatement techniques, since measures to reduce emissions of one nitrogen pollutant can often lead to an increase in another. This project represents a step towards greater understanding of these issues by linking together new and existing nitrogen flux models into a larger framework. The modelling framework has been constructed and some of the nitrogen flows between fields, farms and the atmosphere have been modelled for a UK study area for typical farm management scenarios.  相似文献   
128.
Amino acids constitute one of the largest inputs of organic nitrogen (N) to most polar soils and have been hypothesized to be important in regulating vegetational succession and productivity in Arctic ecosystems. Our understanding of amino acid cycling in these soils, however, is poor. The aim of this study was to investigate the size and rate of turnover of the amino acid pool in a range of Arctic and Antarctic soils. Our results indicate that in polar soils with either high or low ornithogenic inputs the amino acid pool is small in comparison to the inorganic N pool (NO3 and NH+4). The free amino acid pool constituted only a small proportion of the total dissolved organic nitrogen (DON) pool in these soils. Here we show that these low concentrations may be due to rapid use by the soil microbial community in both Arctic and Antarctic soils. The turnover of the amino acid pool in soil was extremely rapid, with a half-life ranging from 2 to 24 h, indicating that this N pool can be turned over many hundred times each summer when polar soils are frequently unfrozen. The implications of amino acids in N cycling and plant and microbial nutrition are discussed.  相似文献   
129.
Impact of Land Use on Soluble Organic Nitrogen in Soil   总被引:5,自引:0,他引:5  
Although it has been hypothesized that soluble organic nitrogen (SON) plays a central role in regulating productivity in some terrestrial ecosystems, the factors controlling the size of the SON pool in soil remain poorly understood. Therefore our principal aim in this work was to assess the impact of seven different land use systems (rough and managed grassland, deciduous and coniferous woodland, heathland, wetland and tilled land) on the size of the SON and inorganic N (NO 3 , NH 4 + ) pools in the surface soil layer (0–15 cm). After extraction with deionised water, we found that in most cases the size of the water extractable organic N (WEON) pool was similar in size to the inorganic N pool. In contrast, the KCl extractable organic N (KClEON) pool constituted the dominant form of soluble N in soils under all land uses, perhaps indicating that significant amounts were held on the soil exchange phase. In contrast to inorganic N, which varied significantly with land use, the size of the KClEON and WEON pool was similar for all land uses with the exception of KClEON in tilled land, where significantly lower amounts were observed. We conclude that SON constitutes an important soil N pool in a broad range of land uses, and that its role in microbial N assimilation, plant nutrition and ecosystem responses to atmospheric N deposition warrants further attention. SAFRD, University of Newcastle, Newcastle-upon-Tyne, NE1 7RU, U.K.  相似文献   
130.
城市污水除磷技术发展   总被引:8,自引:4,他引:8  
侯红娟  周琪 《四川环境》2004,23(6):41-44,49
磷是水体富营养化的一个主要限制因素,控制出水中磷的浓度尤其重要。污水除磷方法有生物除磷、化学除磷及生态除磷,也可将各种方法组合使用,如生物一化学除磷、生物一生态除磷等,实际应用中应根据具体情况选择适宜的除磷方法。  相似文献   
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