Influence of liquid- and solid-state coupling anaerobic digestion process on methane production of cow manure and rice straw

Journal of Material Cycles and Waste Management - Based on the different characteristics of cow manure and rice straw, liquid- and solid-state coupling anaerobic digestion (L-SS-AD) is designed in...     

汽车尾气排放与大气污染

随着汽车工业的迅猛发展,汽车在带给人们生活方便和快捷的同时,也给人类生存环境造成了污染。文章阐述了当前国内外汽车尾气排放污染现状,并详细介绍了汽车尾气中一氧化碳、氮氧化物、二氧化硫、碳氢化合物等有害物质以及所产生的臭气、噪声、二氧化碳等对环境及人体健康的危害。     

Temperature,salinity, and prey effects on polyp versus medusa bud production by the invasive hydrozoan<Emphasis Type="Italic"> Moerisia lyonsi</Emphasis>

Hydrozoan species are renowned for flexible asexual reproduction, which may predispose them to be successful invaders. Polyps of the invasive hydrozoan Moerisia lyonsi (Boulenger, 1908) have very high rates of asexual production of both polyp and medusa buds. In order to determine how environmental factors affect asexual reproduction in M. lyonsi, the quantitative relationships between polyp bud and medusa bud production were studied in a 31-day laboratory experiment during August 2001. The combined effects of prey (4, 8, 12, 16 Acartia tonsa copepods polyp^–1 day^–1), temperature (20°C, 29°C), and salinity (5, 15, 25) were tested on the development times for polyp buds (DT_p) and medusa buds (DT_m), the total asexual reproduction rate (ARR, no. buds polyp^–1 day^–1), and the ratio of medusa bud to total bud production (R_m). Greater food consumption significantly and directly enhanced ARR and R_m and shortened DT_p and DT_m. A lower temperature (20°C) and higher salinity (25) reduced food consumption, lengthened development times, and decreased ARR and R_m, with opposite effects for the higher temperature (29°C) and lowest salinity (5). The patterns of variation of these reproductive parameters are more complex. DT_m was most sensitive and was significantly and directly affected by all three measured factors. In addition to food consumption, direct effects were seen by temperature on DT_p and by salinity on R_m. ARR was directly affected only by food consumption. Overall, DT_p, DT_m, and R_m were more sensitive to environmental differences than was ARR. More favorable conditions enhanced medusa bud production. The adaptive reproductive processes and their significance for the maintenance and dispersal of M. lyonsi are discussed.Communicated by J.P. Grassle, New Brunswick     

便携式空调系统研究

在炎热环境中,便携式空调系统可以对人的身体进行冷热调节,创造一种微气候环境。根据Natick士兵中心研究结果:只要提供300 W制冷量就能满足一个人的热负荷需求。北京工业大学研制了微型蒸汽压缩制冷系统作为便携式空调的冷源,微型制冷系统的制冷量为300 W,重量为2．85 kg,几何尺寸为270 mm×260 mm×120 mm。采用强化传热措施及轻质材料来减小微型制冷系统的重量及体积。     

伊利金川污水处理厂的设计与运行

根据乳品生产中产生的污水水质特点,对伊利金川污水处理厂采用“调节-隔油-UASB-SBR”工艺进行了工程设计。运行结果表明,采用UASB工艺处理乳品生产中的污水,绝大部分有机物可由厌氧微生物进行降解及去除,每天可减少供氧能耗约7900kW·h,每年可节约电费约130万元。出水水质符合GB8978-1996《污水综合排放标准》中的一级标准。同时,污水处理厂每天可产生约14300m3沼气(含9875m3甲烷),相当于9.8吨标准煤。沼气可用于低压锅炉燃烧原料,对于缓解目前能源日益紧缺的压力和发展企业的循环经济具有非常重要的意义。该工艺还具有路线短及能源回收等优点,实用性强。     

比较研究：完善失业保险促进就业功能

失业保险制度产生于20世纪初.在发展初期,以强调基本生活保障为主.20世纪70年代,西方国家充分就业的阶段宣告结束.到了80年代,由于石油危机的影响,通货膨胀严重,国际竞争更趋激烈,很多国家的失业率大幅攀升,形成了自20世纪30年代以来最严重的失业局面.为减轻失业压力,很多国家大幅度改革了失业保险制度和公共就业服务制度.     

纺织品综合色牢度试验方法标准的研究

色牢度是有色纺织品的重要考核指标，单项色牢度往往不能真实反映出纺织品在实际使用时的真实牢度，有时各种单项牢度指标都很好，而在实际穿着或使用时仍会出现问题。本方法标准是在试验室中人工模拟有色纺织品在人体穿用及自然气候等复杂条件下，于短期内（2-4天），可预测出在不同纬度地区实际穿着一定时间后颜色的变化情况。本方法不仅适用于军用纺织品，同样也适用于民用所有有色纺织品。可依据用户的不同要求，确定试验周期，来反映某一地区一个阶段后颜色变化的真实情况。还可为纺织印染行业的工艺设计及染料选择，提供综合，快速，准确，科学有效的检测方法。     

Relationship between compost stability and extractable organic carbon

Establishing a simple yet reliable compost stability test is essential for a better compost quality control and utilization efficiency. The objective of this study was to examine the relationship between extractable organic carbon (OC) and compost stability based on 18 compost samples from five composting facilities. The compost samples were extracted sequentially with water for 2 h [water(2h)] and 0.1 M NaOH for 2 and 24 h [NaOH(2h) and NaOH(24h), respectively]. The extractable OC was further separated into fulvic acid (FA) and humic acid (HA) fractions by adjusting the pH to <2. The mass specific absorbance (MSA) of OC in the six fractions was measured. Compost stability was estimated with a CO2 evolution method. The extractable OC concentration was influenced by the total volatile solids and decreased with curing time for compost with a high level of extractable OC. The OC levels in each fraction were significantly correlated (p < 0.05) to each other except for the water(2h)-extractable HA. In addition, all the FA and HA fractions except for water(2h)-extractable HA were highly (P < 0.01) and linearly correlated to CO2 evolution, but multiple regression showed that NaOH(24h)-extractable OC was insignificant for CO2 evolution. The relatively high slope of NaOH(2h)-extractable FA versus CO2 evolution suggests that this fraction may contribute the most to compost CO2 evolution. The water(2h)- and/or NaOH(2h)-extractable FA tests are recommended for measuring compost stability because of their high correlation with CO2 evolution. This estimation can be obtained through a simple photometric method covering a wide range of carbon concentrations up to 4,000 mg L(-1).