避洪耐涝生态农业的发展方向与思路——洞庭湖退田还湖区案例研究

在退田还湖区发展避洪耐涝生态农业，是提高移民收入、脱贫致富奔小康、提高移民安置质量和拓展安置容量的重要途径。根据洞庭湖区的农业优势和退田还湖区发展高效生态农业的基础和条件，将其发展的总体方向确定为实现避洪耐涝高效特色生态农业产业化。其基本思路是：（1）双退垸行洪区面对洪水渍水重点发展耐涝性强的水生蔬菜、水生饲料及特种名优渔类产业；（2）单退垸区避开洪水重点发展粮油、林草、畜牧业等主导产业；面对洪水、渍水发展耐涝性强的水禽和特种水产养殖业；（3）蓄洪垸区避开特大洪水大力发展粮食、经济作物，突出发展草食牧畜业，积极发展水禽和特种渔类养殖业。通过发展差异性的避洪耐涝生态农业，建设具有支柱产业链特色的粮油生产基地、畜禽生产基地、林木、蔬菜生产基地，特种水产养殖基地，最终实现高效生态农业产业化。     

呼吸防护用品的人机工效学问题分析

呼吸防护用品符合人的形态与生理特征,才能保证其防护效果和舒适性。笔者从人体的面部形态与生理机能角度,分析了呼吸防护用品与人体的适配性,系统提出密合性、呼吸阻力、死腔、视野等呼吸防护用品的人机工效学问题。该论文取得的成果,对进一步丰富呼吸防护用品人机工效学研究内容,指导呼吸防护用品的设计与生产,提升我国呼吸防护用品的防护效果与核心竞争力,以期发挥积极的推动作用。     

Ozone Deposition to a Coniferous and Deciduous Forest in the Czech Republic

Estimates of ozone concentration and deposition flux to coniferous and deciduous forest in the Czech Republic on a 1 × 1 km grid during growing season (April–September) of the year 2001 are presented. Ozone deposition flux was derived from ozone concentrations in the atmosphere and from its deposition velocities. To quantify the spatial pattern in surface concentrations at 1 km resolution incorporating topography, empirical methods are used. The procedure maps ozone concentrations from the period of the day when measurements are representative for the forest areas of countryside. The effects of boundary layer stability are quantified using the observed relationship between the diurnal variability of surface ozone concentration and altitude. Ozone deposition velocities were calculated according to a multiple resistance model incorporating aerodynamic resistance (R _a ), laminar layer resistance (R _b ) and surface resistance (R _c ). Surface resistance (R _c ) comprises stomatal resistance (R _sto ). R _sto was calculated with respect to global radiation, surface air temperature and land cover. Modelled total and stomatal ozone fluxes are compared with the maps describing equivalent values of AOT40 (accumulated exposure over threshold of 40 ppb). For forests, the critical level (9,000 ppbh May–July daylight hours) is exceeded over 50% of forested territory. This indicates the potential for effects on large areas of forest. There is significiant correspondence between the exposure index AOT40 and the total ozone flux, but the relation between the total ozone flux and AOT40 exposure index is not clear in all parts of the forest territory.     

Laboratory Measurement of Dry Deposition of Ozone onto Northern Chinese Soil Samples

We used laboratory experiments to investigate surface resistance (R _c) to dry deposition of ozone (O₃) on different types of soil samples collected from the arid deserts and the Loess Plateau of northern China. Furthermore, we measured the factors that affected R _c, which depends on the physical and chemical interaction between trace constituents and the deposition surface, and evaluated deposition velocity (V _d). There was little influence of geometric surface area, soil weight, or O₃ concentration on V _d of O₃. The effect of relative humidity (RH) (i.e. moisture content of the soil) on O₃ uptake was in agreement with results reported in the literature: a distinct RH dependence of V _d and little uptake under water-saturated conditions were observed. R _c values for all the soil samples examined were in the range 0.21–3.3 s mm⁻¹ and were exponentially related to the surface area of the particles and the organic carbon content of each soil sample at RH of both <10 and 60%.     

滤毒过滤器的设计与阻力确定

在危险化学品生产和销毁工厂的通风系统中一定要设置滤毒装置, 介绍了滤毒过滤器的设计与阻力确定方法.     

Impacts of Camping on Vegetation: Response and Recovery Following Acute and Chronic Disturbance

Experiments with controlled levels of recreational camping were conducted on previously undisturbed sites in two different plant communities in the subalpine zone of the Wind River Mountains, Wyoming, USA. The plant communities were coniferous forest with understory dominated by the low shrub Vaccinium scoparium and a riparian meadow of intermixed grasses and forbs, of which Deschampsia cespitosa was most abundant. Sites were camped on at intensities of either one or four nights per year, for either one (acute disturbance) or three consecutive years (chronic disturbance). Recovery was followed for three years on sites camped on for one year and for one year on sites camped on for three years. Reductions in vegetation cover and vegetation height were much more pronounced on sites in the forest than on sites in the meadow. In both plant communities, increases in vegetation impact were not proportional to increases in either years of camping or nights per year of camping. Close to the center of campsites, near-maximum levels of impact occurred after the first year of camping on forested sites and after the second year on meadow sites. Meadow sites recovered completely within a year, at the camping intensities employed in the experiments. Forest sites, even those camped on for just one night, did not recover completely within three years. Differences between acute and chronic disturbance were not pronounced.     

EVAPOTRANSPIRATION AND CANOPY RESISTANCE AT AN UNDEVELOPED PRAIRIE IN A HUMID SUBTROPICAL CLIMATE1

ABSTRACT: Reliable estimates of evapotranspiration from areas of wildland vegetation are needed for many types of water-resource investigations. However, little is known about surface fluxes from many areally important vegetation types, and relatively few comparisons have been made to examine how well evapotranspiration models can predict evapotranspiration for soil-, climate-, or vegetation-types that differ from those under which the models have been calibrated. In this investigation at a prairie site in west-central Florida, latent heat flux (λE) computed from the energy balance and alternatively by eddy covariance during a 15-month period differed by 4 percent and 7 percent on hourly and daily time scales, respectively. Annual evapotranspiration computed from the energy balance and by eddy covariance were 978 and 944 mm, respectively. An hourly Penman-Monteith (PM) evapotranspiration model with stomatal control predicated on water-vapor-pressure deficit at canopy level, incoming solar radiation intensity, and soil water deficit was developed and calibrated using surface fluxes from eddy covariance. Model-predicted λE agreed closely with λE computed from the energy balance except when moisture from dew or precipitation covered vegetation surfaces. Finally, an hourly PM model developed for an Amazonian pasture predicted λE for the Florida prairie with unexpected reliability. Additional comparisons of PM-type models that have been developed for differing types of short vegetation could aid in assessing interchangeability of such models.     

天津市煤气管网的震害预测及可靠性分析

本文研究了地下管道系统的震害预测及网络系统可靠性分析的方法。它是以地下管道微观破坏机制为根据,以模糊图论为主要计算工具的计算方法。最后,本文给出了天津市煤气管网系统的应用实例,结果表明,本方法有一定的推广应用价值。     

铁炭内电解预处理阿维菌素废水

采用铁炭内电解预处理阿维菌素废水，当原水pH为3.7、COD为31600mg/L、AVM含量为204μg/L时，最佳工艺条件为铁炭比1：1、停留时间30min、混凝pH8－9时，废水COD和AVM的去除率分别达到19.5%和68.5%，为后续生化处理创造了有利条件。     

城市抗震防灾场地小区划管理系统开发研究

介绍场地小区划管理系统的基本结构和开发。利用数据库管理系统和实用软件能够解决数据库管理、数据分析、数据查询、图形显示等功能。通过在河南省的某城市的实际应用表明，该系统对于城市抗震防灾规划的研究工作和城市工程地质的管理工作中，都提供了一个较好的辅助工作手段。