南充市空气中可吸入颗粒物污染水平分析

本文在连续1年又5个月同步采样的基础上，测得南充市市辖三城区5个采样监测点环境空气中PM10的浓度及其时空变化进行了分析。结果表明，PM10的日平均浓度范围为0．020～1．030mg／m^3，超标率达38．0％；周日均浓度在0.040～0．520mg／m^3之间，超标率达到了37．8％。空气污染最重为嘉陵城区，其次为高坪城区，再次为石油学院、炼油厂和市府二院。浓度季节变化特征表现为冬季最高，其次为秋季，再次为春季，最轻为夏季。     

新疆中低产田发展人工草地的初步研究

从新疆天然草地的利用，农业面临的问题出发，说明在绿洲内发展人工草地的必要性。针对全疆中低产田特点，将其分成7种基本类型。按类型总结出相应适生的饲草种类。通过人工种植这些饲草，达到合理利用改良耕地的目的，进而带动整个农业产业结构的调整，建立起适宜新疆农业发展的草地农业模式。     

用差示分光光度法测定高浓度皮革废水中铬的方法探讨

介绍了应用差示分光光度法直接测定高浓度皮革废水中Cr的方法，通过与原实验方法分析结果的对比，获得了满意的结果，能基本满足环境监测的要求。     

长袋低压脉冲除尘器的创新与发展

依靠科技进步，应用多项专利技术，研制与开发的LFDM型长袋低压脉冲除尘器，成功应用于冶金、有色、建材、电力、机械和矿业等行业的工业气体除尘与净化；具有明显的达标排放和占地小、阻力低、投资省、运行费用少等特点。     

气浮+生物接触氧化工艺处理食品加工废水

通过气浮 生物接触氧化工艺处理速冻食品加工废水的实验、设计和工程运行,结果表明:废水COD去除率能达到97%以上,使得最终出水的COD＜100mg/l.该工艺对冲击负荷有较强的适应性.     

The Ethics of Constrained Choice: How the Industrialization of Agriculture Impacts Farming and Farmer Behavior

The industrialization of agriculture not only alters the ways in which agricultural production occurs, but it also impacts the decisions farmers make in important ways. First, constraints created by the economic environment of farming limit what options a farmer has available to him. Second, because of the industrialization of agriculture and the resulting economic pressures it creates for farmers, the fact that decisions are constrained creates new ethical challenges for farmers. Having fewer options when faced with severe economic pressures is a very different situation for farmers than having many options available. We discuss the implications of constrained choice and show that it increases the likelihood that farmers will consider unethical behavior.     

SUMMER LOW FLOWS IN NEW ENGLAND DURING THE 20TH CENTURY1

ABSTRACT: High springtime river flows came earlier by one to two weeks in large parts of northern New England during the 20th Century. In this study it was hypothesized that late spring/early summer recessional flows and late summer/early fall low flows could also be occurring earlier. This could result in a longer period of low flow recession and a decrease in the magnitude of low flows. To test this hypothesis, variations over time in the magnitude and timing of low flows were analyzed. To help understand the relation between low flows and climatic variables in New England, low flows were correlated with air temperatures and precipitation. Analysis of data from 23 rural, unregulated rivers across New England indicated little evidence of consistent changes in the timing or magnitude of late summer/early fall low flows during the 20th Century. The interannual variability in the timing and magnitude of the low flows in northern New England was explained much more by the interannual variability in precipitation than by the interannual variability of air temperatures. The highest correlation between the magnitude of the low flows and air temperatures was with May through November temperatures (r =?0.37, p= 0.0017), while the highest correlation with precipitation was with July through August precipitation (r = 0.67, p > 0.0001).     

BASE FLOW RECESSION RATES,LOW FLOWS,AND HYDROLOGIC FEATURES OF SMALL WATERSHEDS IN PENNSYLVANIA,USA1

This paper examines the relationships between measurable watershed hydrologic features, base flow recession rates, and the Q_7,10 low flow statistic (the annual minimum seven‐day average streamflow occurring once every 10 years on average). Base flow recession constants were determined by analyzing hydrograph recession data from 24 small (>130 km²), unregulated watersheds across five major physiographic provinces of Pennsylvania, providing a highly variable dataset. Geomorphic, hydrogeologic, and land use parameters were determined for each watershed. The base flow recession constant was found to be most strongly correlated to drainage density, geologic index, and ruggedness number (watershed slope); however, these three parameters are intercorrelated. Multiple regression models were developed for predicting the recession rate, and it was found that only two parameters, drainage density and hydrologic soil group, were required to obtain good estimates of the recession constant. Equations were also developed to relate the recession rates to Q_7,10 per unit area, and to the Q_7,10/Q₅₀ ratio. Using these equations, estimates of base flow recession rates, Q_7,10, and streamflow reduction under drought conditions can be made for small, ungaged basins across a wide range of physiography.     

低气压试验标准及试验技术分析

详细阐述了低气压环境对装备的各种影响,介绍了我国主要军用、民用环境试验标准中规定的试验程序及其应用对象,分析了有关低气压试验条件,包括低气压贮存、工作和快速/爆炸减压的试验条件和变化速率,最后简单介绍了低气压试验设备的一般要求、特别是快速减压和爆炸减压设备的使用和低气压试验技术。     

受限空间内惰性气体对CH4爆炸抑制特性研究

N2和CO2是常用的惰性抑爆气体,为研究两种气体的抑爆特性,采用20L球形爆炸试验装置,分析了不同浓度配比条件下N2/CH4/空气以及CO2/CH4/空气混合气体的爆炸压力,同时采集爆炸后的气体样品,对比分析爆炸后残留气体的主要成分。结果显示:随CH4浓度从5%增加至12.5%时,完全抑制CH4爆炸需要的惰性气体最小量先增大后降低,CH4浓度在6.5%~7.5%之间时,抑爆需要的惰性气体的量最大;在同一CH4浓度条件下,抑爆需要N2的量大于CO2,并且CH4浓度在5%~6.5%时,抑爆需要两种惰性气体的量值差别最大;当CH4浓度一定时,随着加入惰性气体量的增大,爆炸最大超压逐渐降低,惰性气体浓度和爆炸超压之间基本呈线性关系;在同样条件下,相对于N2,CO2为抑爆气体时,爆炸后腔体内残留的CH4浓度较高。研究成果为惰性气体抑爆技术提供技术支撑,同时为揭示惰性气体抑爆机理有一定作用。