大型泵站拦污清污方案选择

介绍了泵站常用的拦污、清污方式。结合谏壁抽水站的具体情况，给出了斜式拦污栅的结构设计、布置方式；对抓斗式、回转式两种形式清污装置的方案进行了比较，结论是：抓斗式清污机造价低、施工容易、维修方便、可靠性好、具有较高综合利用价值，更适合污物较多的泵站。     

Treatment of pigs with enrofloxacin via different oral dosage forms – environmental contaminations and resistance development of Escherichia coli

BackgroundAntibacterial agents play important roles in the treatment of bacterial infections. However, the development of antimicrobial resistance (AMR) and carry-over of substances into the environment are several problems arising during oral treatment of bacterial infections. We assessed AMR development in commensal Escherichia coli (E. coli) in enrofloxacin treated and untreated animals. In addition, we examined fluoroquinolone in the plasma and urine of treated and untreated animals, and in sedimentation dust and aerosol.MethodsIn each trial, six pigs were treated with enrofloxacin via powder, granulate or pellet forms in two time periods (days 1–5 and 22–26). Four pigs served as untreated controls. The minimum inhibitory concentration (MIC) was determined to evaluate AMR development. Analysis of enro- and ciprofloxacin was performed with high performance liquid chromatography.ResultsNon-wildtype E. coli (MIC > 0.125 µg/mL) was detected in the pellet treated group after the first treatment period, whereas in the other groups, non-wildtype isolates were found after the second treatment period. E. coli with MIC > 4 µg/mL was found in only the pellet trial. Untreated animals showed similar susceptibility shifts several days later. Bioavailability differed among the treatment forms (granulate > pellet > powder). Enro- and ciprofloxacin were detected in aerosols and sedimentation dust (granulate, powder > pellet).ConclusionsThis study indicates that the kind of the oral dosage form of antibiotics affects environmental contamination and AMR development in commensal E. coli in treated and untreated pigs.     

沙尘天气对兰州市城区环境空气质量影响研究

以2013年3月8 ～15日兰州市发生的系统性沙尘天气为例,分析了兰州市PM10、TSP以及能见度等污染物及气象因子对兰州市城区环境空气质量的影响.结果表明,此次沙尘天气甘肃始发地在河西走廊酒泉地区,主要受强冷空气影响,沙尘在风力影响下远距离输送,8日17：00在酒泉市发生时,大气最低能见度3.4 km,可吸入颗粒物最大浓度14.74 mg/m3,23：00影响到兰州等地,对甘肃省大部分地区影响较大,尤其对兰州市环境空气质量影响较大;受沙尘天气的影响,8 ～15日兰州市环境空气质量7d为重污染,1d为中度污染,首要污染物为可吸入颗粒物;能见度和可吸入颗粒物有明显的的负相关关系,湿度对能见度和颗粒物浓度的拟合存在影响.     

国外木材工业企业的热能源自给技术

本文介绍了国外木材加工企业实现热能源自给的高效，节能除尘－供热系统。     

我国中密度纤维板生产线气力输送及除尘系统能耗浅析

单位产品综合能耗高是我国中密度纤维板工业存在的主要问题之一。气力输送与除尘装置的能耗占有相当比例。 对其高能耗状况和原因进行分析,在系统设计、使用和设备管理方面采取措施,气力输送与除尘装置具有较大的节能潜力。     

Investigating the Link between Particulate Exposure and Airway Inflammation in the Horse

Inhalant exposure to airborne irritants commonly encountered in horse stables is implicated in the pathogenesis of inflammatory airway disease (IAD) and recurrent airway obstruction (RAO), non‐infectious, inflammatory pulmonary disorders that impact the health and performance of horses across all equine disciplines. IAD and RAO have overlapping clinical, cytological, and functional manifestations of the pulmonary response to organic dust and noxious gases encountered in the barn environment. Study of these diseases has provided important but incomplete understanding of the effect of air quality upon the respiratory health of horses. In this review, the principles of particulate exposure assessment, including health‐related aerosol size fractions and size‐selective sampling, the factors influencing air quality in equine environments, and the effect of air quality on the equine respiratory tract are discussed. The objective of this review is to provide the reader with a summary of the most common chronic inflammatory airway diseases in the horse and the principles of air sampling that are essential to the planning, interpretation, and assessment of equine respiratory health‐related exposure studies.     

构树对菱镁矿区破损土地的生态适应性

[目的]研究菱镁矿粉尘对土壤理化性质的影响以及构树对镁粉尘污染土壤的耐受性.[方法]采用盆栽试验,室内模拟氧化镁粉尘沉降、人工掺和废矿堆.[结果]当镁粉尘施加量小于10％时,促进构树生长,当土壤镁含量为4.17 g/kg时,构树单株生物量达3.46g,明显大于洁净土壤的生物量（2.81 g）;构树对生长土质的要求低,土壤中矿石含量25％时,生物量最大为6.12g,明显比洁净土壤生物量高出3.31 g;施加镁粉尘明显改变了构树生长土壤的理化性质,pH由6.78升到9.48,电导率先增加到651.8 μS/cm后降至375.7 μS/cm,速效磷含量从52.1 mg/kg降至16.9 mg/kg,全镁含量从1.403 g/kg升至9.015 g/kg.[结论]构树对镁具有较强耐受能力,并对生长土质要求低,在不同程度破损土质中均能健康生长,在修复菱镁矿区镁污染土地方面具有相当大的潜力.     

平均铣削厚度对MDF铣削粉尘粒度分布及表面粗糙度的影响

研究了不同平均铣削厚度条件下MDF铣削粉尘粒度分布状态及典型粒度粉尘的形态,并在此基础上测试了MDF铣削表面的粗糙度。结果表明,铣削MDF粉尘粒度分布主要集中在0.5～450.0μm,铣削MDF粉尘颗粒基本上为狭长型纤维状。随着平均铣削厚度的增加,MDF粉尘的平均粒度{D（4,3）,D（3,2）}及中位径D（50）呈逐渐增大的趋势,而铣削速度影响较进给速度影响明显。随着平均铣削厚度的增加,MDF铣削表面质量降低,而铣削速度影响较进给速度影响明显。     

密集烤房群应用烟气处理系统的研究

[目的]降低密集烤房群的颗粒物和二氧化硫排放量,减少其对环境的污染。[方法]在密集烤房群建造烟气处理系统,通过管道连接将烤房烟囱排放的烟气输送到除尘脱硫塔中,使烟气先进行碱水净化处理,然后再排放到大气中。[结果]试验表明,处理后的烟气中的颗粒物排放浓度(59.75 mg/m3)较处理前(156.35 mg/m3)减少了96.65 mg/m3,减幅为61.82%;SO2排放浓度(7 193.5 mg/m3)较处理前(9 062.9 mg/m3)减少了1 869.4 mg/m3,减幅为20.63%。[结论]烟叶密集烤房的烟气经除尘脱硫装置处理后,颗粒物和SO2的排放浓度大幅降低,有利于环境保护。     

Dust storm erosion and its impact on soil carbon and nitrogen losses in northern China

There is increased awareness of the environmental impacts of soil carbon (C) and nitrogen (N) losses through wind erosion, especially in areas heavily affected by dust storm erosion. This paper reviews the recent literature concerning dust storm-related soil erosion and its impact on soil C and N losses in northern China. The purpose of our study is to provide an overview of the area of erosion-affected soils and to estimate the magnitude of soil C and N losses from farmland affected by dust storm erosion.According to the second national soil erosion remote-sensing survey in 2000, the area affected by wind erosion was 1.91 million km², accounting for 20% of the total land area in China. This area is expanding quickly as the incidence of heavy dust storms has greatly increased over the last five decades, mainly as a result of the intensification of soil cultivation. The economic and ecological damage caused by wind erosion is considerable. Heavily affected areas show a loss of nutrients and organic carbon in soils and the heavily degraded soils are much less productive. Compared with the non-degraded soil, the C and N contents in degraded soils have declined by 66% and 73%, respectively. The estimated annual losses per cm toplayer of soil C and N by dust storm erosion in northern China range from 53 to 1044 kg ha^− 1 and 5 to 90 kg ha^− 1, respectively. Field studies suggest that soil losses by wind erosion can be reduced by up to 79% when farmers shift from conventional soil tillage methods to no-till. Thus shifting to no-till or reduced tillage systems is an effective practice for protecting soil and soil nutrients. Our study indicates that soil conservation measures along with improved soil fertility management measures should be promoted in dry-land farming areas of northern China. As erosion is a major mechanism of nutrient withdrawal in these areas, we plead for the development of accurate methods for its assessment and for the incorporation of erosion, as a nutrient output term, in nutrient budget studies.