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61.
本文介绍了大气中微量汞的一种监测方法,利用汞富集解析器富集大气中的微量汞.解析后用冷原子吸收法测定.研究了FJ-1型汞富集解析器与WYX-405原子吸收分光光度计联用的工作条件,相对标准偏差为1.7%. 相似文献
62.
南宁市主要以堆肥和填埋方式处理生活垃圾,由于二次污染而对外界环境造成影响,应尺快实现堆肥,焚烧,填埋有机融合的“三合一”生活垃圾综合处理工程,逐步实现生活垃圾处理无害化,减变化,资源化的目标。 相似文献
63.
The environmental performance of hemp based natural fiber mat thermoplastic (NMT) has been evaluated in this study by quantifying carbon storage potential and CO2 emissions and comparing the results with commercially available glass fiber composites. Non-woven mats of hemp fiber and polypropylene matrix were used to make NMT samples by film-stacking method without using any binder aid. The results showed that hemp based NMT have compatible or even better strength properties as compared to conventional flax based thermoplastics. A value of 63 MPa for flexural strength is achieved at 64% fiber content by weight. Similarly, impact energy values (84–154 J/m) are also promising. The carbon sequestration and storage by hemp crop through photosynthesis is estimated by quantifying dry biomass of fibers based on one metric ton of NMT. A value of 325 kg carbon per metric ton of hemp based composite is estimated which can be stored by the product during its useful life. An extra 22% carbon storage can be achieved by increasing the compression ratio by 13% while maintaining same flexural strength. Further, net carbon sequestration by industrial hemp crop is estimated as 0.67 ton/h/year, which is compatible to all USA urban trees and very close to naturally, regenerated forests. A comparative life cycle analysis focused on non-renewable energy consumption of natural and glass fiber composites shows that a net saving of 50 000 MJ (3 ton CO2 emissions) per ton of thermoplastic can be achieved by replacing 30% glass fiber reinforcement with 65% hemp fiber. It is further estimated that 3.07 million ton CO2 emissions (4.3% of total USA industrial emissions) and 1.19 million m3 crude oil (1.0% of total Canadian oil consumption) can be saved by substituting 50% fiber glass plastics with natural fiber composites in North American auto applications. However, to compete with glass fiber effectively, further research is needed to improve natural fiber processing, interfacial bonding and control moisture sensitivity in longer run. 相似文献
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随着节能减排政策的深入实施,关于烟气排放的标准也越来越严格,在超低排放的工程改造中,需要加大对固定污染烟气排放的实时监测,才能达到相应的规范和排放标准,因此紫外差分分析仪在烟气超低排放监测中得到了推广和应用,本文就烟气监测采样技术和分析方法进行分析,针对紫外差分分析仪的各项指标,通过实验室检测结果和最新国家标准之间的对比,对其超低排监测中的应用进行探讨。 相似文献
67.
喷烤漆房内的污染物传播及火灾控制是喷烤漆房设计和使用时的重中之重,设计有效、合理的通风系统可很好地规避这一问题。以某喷烤漆房为原型建立了物理模型,应用数值模拟方法构建了喷漆过程中污染物扩散过程,并研究了产生均匀流的通风系统设计以及不同均匀流速对污染物扩散的影响规律。研究表明,采用纤维布形式可简单高效地构建静压箱结构形成均匀流。文中还建立了纤维布、过滤棉多孔介质模型,结果表明当均匀流速度为0.91 m/s时,喷漆人员面部附近的甲苯浓度降至喷射浓度的0.02%,远低于危害值。 相似文献
68.
不同原理分析仪观测大气中氮氧化物对比研究 总被引:4,自引:0,他引:4
氮氧化物(NOx)是大气二次光化学污染臭氧的重要前体物,但目前对其总量和分量的测量仍存在着一些难以解决的问题。选择3种不同原理的市售氮氧化物分析仪在广东和北京进行比对观测实验,从而比较其各自的优缺点及适用性。结果表明,钼转化法(MC)测得的NOx比光转化法(LC)及液相化学发光法(LPC)所测得的值都明显偏高,可近似认为是NOy。LPC检测NO2时受到PAN等含有—NO2生色基团的干扰,结果比LC略高。LC测得的NOx值与实际大气最为接近。MC测定的NOx比实际值高,但能满足空气质量指标监测的需求;LC能够准确测定大气中的NOx,但造价太高,仅适用于大气化学机理研究;而LPC原理的仪器适合于短时间的航测、高塔和系留艇进行垂直梯度观测。 相似文献
69.
家蝇抗菌蛋白的分离纯化及部分性质 总被引:14,自引:0,他引:14
通过体壁损伤诱导家蝇(Musca domestica)幼虫产生免疫血淋巴,经沸水浴热变性、减压蒸馏浓缩、Sephadex G-15柱脱盐、CM-Sepharose离子交换层析、Sephadex G-50凝胶过滤等步骤,分离得到一种具抗菌活性的蛋白质,并达电泳纯,结果表明,分离物不具血细胞凝集活性,也不是溶菌酶,而是一种未见报道的抗菌蛋白,经SDS-PAGE测得,该抗菌蛋白Mr=12600,等电点为9.8。 相似文献
70.
Kim KY Ko HJ Kim HT Kim YS Roh YM Lee CM Kim CN 《Environmental monitoring and assessment》2007,133(1-3):255-266
This on-site survey study was performed to determine the concentrations and emissions of aerial contaminants in the different
types of swine houses in Korea and then to present beneficial information available for Korean pig producers to manage optimal
air quality in swine house. The swine houses investigated in this research were selected based on three criteria; manure removal
system, ventilation mode and growth stage of swine. Mean concentrations of aerial pollutants in swine houses were 8 ppm for
ammonia, 300 ppb for hydrogen sulfide, 2 mg m−3 for total dust, 0.6 mg m−3 for respirable dust, 4 log(cfu m−3) for total airborne bacteria and 3 log(cfu m−3) for total airborne fungi, respectively. Mean emissions based on pig (liveweight; 75 kg) and area (m2) were 250 and 340 mg h−1 for ammonia, 40 and 50 mg h−1 for hydrogen sulfide, 40 and 50 mg h−1 for total dust, 10 and 15 mg h−1 for respirable dust, 1.0 and 1.3 log(cfu) h−1 for total airborne bacteria and 0.7 and 1.0 log(cfu) h−1 for total airborne fungi, respectively. In general concentrations and emissions of gases were relatively higher in the swine
houses managed with deep-pit manure system with slats and mechanical ventilation mode than the different swine housing types
whereas those of particulates and bioaerosol were highest in the naturally ventilated swine houses with deep-litter bed system. 相似文献