多功能局部放电检测仪的应用研究

介绍了基于超声波测量法的多功能局部放电测量设备的工作原理,以两个实例分析了多功能局部放电检测仪在实际应用中的可靠性.结果表明,该设备能够很好地检测和定位出利用其他局部放电检测手段无法检测到的局部放电信号,具有较高的可靠性.     

Purulent vaginal discharge in grazing dairy cows: Risk factors,reproductive performance,and prostaglandin F2α treatment

The objectives of this study were to assess the association of a 4-point scale of vaginal discharge score (VDS) with time to pregnancy to define criteria for a practical case of purulent vaginal discharge (PVD) in dairy cows, to test the risk factors for PVD, and, finally, the effect of a dose of PGF_2α on cure and reproductive performance. In experiment 1, grazing Holstein cows (n = 2,414) had their vaginal discharge scored at ～32 d in milk (DIM) on a 4-point scale, the effect of VDS on the hazard of pregnancy by 300 DIM was then assessed to derive a case definition of PVD. Risk factors for PVD and self-cure were also assessed. In experiment 2, grazing Holstein cows (n = 6,326) from 5 herds were checked for PVD at ～30 DIM. Cows with PVD were assigned to receive one dose of 500 μg of PGF_2α analog (Cloprostenol; Ciclase, Syntex SA, Buenos Aires, Argentina) per cow (odd ear tag number) or to remain untreated (even tag number). Cure was declared if cows presented clear normal vaginal discharge (VDS-0) at visit 2 (～62 DIM). Data were analyzed with Cox's regression and mixed logistic models. In experiment 1, cows with VDS ≥1 had lower hazard of pregnancy and longer calving to pregnancy interval than cows with VDS-0. This finding was not affected by the time at which the diagnosis was performed. Therefore, a cow ≥21 DIM and having VDS ≥1 was used to define a case of PVD. The odds of PVD were greater in primiparous cows compared with multiparous, in cows with abnormal calving compared with those with normal calving, and in those losing BCS peripartum. In experiment 2, PGF_2α treatment tended to slightly increase the hazard of pregnancy (adjusted hazard ratio = 1.13). Conversely, PGF_2α had no effect on the odds of cure of PVD [adjusted odds ratio (AOR) = 1.19], pregnancy at first service (AOR = 1.03), or pregnancy by 100 DIM (AOR = 0.89) or 200 DIM (AOR = 1.27). In conclusion, cows with VDS ≥1 can be considered to have PVD because of their lower hazard of pregnancy and longer calving to pregnancy interval (up to 48 d). Important risk factors are parity, calving, and body condition score loss peripartum. Optimal time of diagnosis is ≥28 to 35 DIM because cows experience a high self-cure rate. Self-cure is also affected by parity, prepartum BCS, and VDS. Finally, as treatment with one dose of PGF_2α had a small effect on the hazard of pregnancy and no effect on clinical cure, its therapeutic use in grazing dairy cows with PVD is not recommended.     

废旧泡沫塑料在建筑楼板中的应用

利用回收的废旧泡沫塑料配以水泥和建筑用胶粉,按照不同的配比制作了多组泡沫塑料混凝土立方体试件,并进行了抗压强度试验。通过分析材料密度、试件成型效果和牢固性、抗压强度,得到了制作夹芯材料的适宜配比。设计了外形合理、优点突出的夹芯材料圆环体,将其填充在建筑楼板中,分析了楼板的结构特征、材料特征和力学特征,阐明了夹芯材料圆环体在楼板中应用的可行性。通过对夹芯材料圆环体填充楼板的技术经济分析、施工关键措施实施、抗裂性和承载能力计算及测试发现,废旧泡沫塑料的回收及其在建筑楼板中的再利用,不但解决了环境中的白色污染问题,而且没有影响建筑楼板的力学性能,工程应用前景可观。     

Effect of a sulfonated azo dye and sulfanilic acid on nitrogen transformation processes in soil

Introduction of organic dyes into soil via wastewater and sludge applications has been of increasing concern especially in developing or under-developed countries where appropriate management strategies are scarce. Assessing the response of terrestrial ecosystems to organic dyes and estimating the inhibition concentrations will probably contribute to soil remediation studies in regions affected by the same problem. Hence, an incubation study was conducted in order to investigate the impact of a sulfonated azo dye, Reactive Black 5 (RB5) and sulfanilic acid (SA), a typical representative of aromatic sulfonated amines, on soil nitrogen transformation processes. The results apparently showed that nitrogen related processes in soil can be used as bioindicators of anthropogenic stress caused by organic dyes. It was found that urease activity, arginine ammonification rate, nitrification potential and ammonium oxidising bacteria numbers decreased by 10–20% and 7–28% in the presence of RB5 (>20 mg/kg dry soil) and SA (>8 mg/kg dry soil), respectively. Accordingly, it was concluded that organic dye pollution may restrict the nitrogen-use-efficiency of plants, thus further reducing the productivity of terrestrial ecosystems. Furthermore, the response of soil microbiota to SA suggested that inhibition effects of the organic dye may continue after the possible reduction of the parent dye to associated aromatic amines.     

PCB行业实施清洁生产取得的成效（2）——以汕头超声印制板（二厂）有限公司为例

汕头超声印制板（二厂）公司藉“节能减排”的契机，打破经验思维的束缚，把汕头超声印制板公司的成果和理念成功运用到本公司的清洁生产工作中，创造了良好的经济效益和环境效益。     

Optimal Dynamic Monitoring Network Design and Identification of Unknown Groundwater Pollution Sources

The identification of unknown pollution sources is a prerequisite for designing of a remediation strategy. In most of the real world situations, it is difficult to identify the pollution sources without a scientifically designed efficient monitoring network. The locations of the contaminant concentration measurement sites would determine the efficiency of the unknown source identification process to a large extent. Therefore coupled and iterative sequential source identification and dynamic monitoring network design framework is developed. The coupled approach provides a framework for necessary sequential exchange of information between monitoring network and source identification methodology. The preliminary identification of unknown sources, based on limited concentration data from existing arbitrarily located wells provides the initial rough estimate of the source fluxes. These identified source fluxes are then utilized for designing an optimal monitoring network for the first stage. Both the monitoring network and source identification process is repeated by sequential identification of sources and design of monitoring network which provides the feedback information. In the optimal source identification model, the Jacobian matrix which is the determinant for the search direction in the nonlinear optimization model links the groundwater flow-transport simulator and the optimization method. For the optimal monitoring network design, the integer programming based optimal design model requires as input, simulated sets of concentration data. In the proposed methodology, the concentration measurement data from the designed and implemented monitoring network are used as feedback information for sequential identification of unknown pollution sources. The potential applicability of the developed methodology is demonstrated for an illustrative study area.     

Indoor exposure to particulate matter and the incidence of acute lower respiratory infections among children: A birth cohort study in urban Bangladesh

Approximately half of all children under two years of age in Bangladesh suffer from an acute lower respiratory infection (ALRI) each year. Exposure to indoor biomass smoke has been consistently associated with an increased risk of ALRI in young children. Our aim was to estimate the effect of indoor exposure to particulate matter (PM_2.5) on the incidence of ALRI among children in a low‐income, urban community in Bangladesh. We followed 257 children through two years of age to determine their frequency of ALRI and measured the PM_2.5 concentrations in their sleeping space. Poisson regression was used to estimate the association between ALRI and the number of hours per day that PM_2.5 concentrations exceeded 100 μg/m³, adjusting for known confounders. Each hour that PM_2.5 concentrations exceeded 100 μg/m³ was associated with a 7% increase in incidence of ALRI among children aged 0–11 months (adjusted incidence rate ratio (IRR) 1.07, 95% CI 1.01–1.14), but not in children 12–23 months old (adjusted IRR 1.00, 95% CI 0.92–1.09). Results from this study suggest that reducing indoor PM_2.5 exposure could decrease the frequency of ALRI among infants, the children at highest risk of death from these infections.     

Environmental crisis in Bhilai,an industrial complex of Madhya Pradesh,India

The emergence of Bhilai on the industrial scene of India and its growth and development as an industrial complex are a significant landmark in the history of industrialization of the country. In our paper an attempt is made to identify the emerging environmental problems associated with the infra‐structural facilities of the study area, a backward and neglected poverty stricken part of the country. In the area, air, water and noise pollution arise from the emissions of the iron and steel plants. There is no provision for sewage and water disposal. Industrial waste is another serious problem for the complex, e.g. slags from the steel furnaces. Bhilai also suffers from slums and overcrowding. Bearing these facts in view, some suitable suggestions for the proper environmental planning of the area are made.     

钢铁、钛和铝工业废渣在去除水中重金属和酸性中的作用

选取钢铁工业废渣中的钒钛磁铁矿选铁尾矿渣、钒钛磁铁矿含钛高炉渣、普通高炉渣、钢渣,钛工业废渣中的钒钛磁铁矿选钛尾矿渣和铝工业废渣中的赤泥作为研究对象,通过圆柱试验以检验其对水中重金属Cd2＋、Co2＋、Cu2＋、Mn2＋、Ni2＋、Zn2＋和酸性的去除能力。这6种工业废渣对水中的Cd2＋的吸附容量为278~6 811 mg/kg,对Co2＋的吸附容量为127~6 052 mg/kg,对Cu2＋的吸附容量为442~53 566 mg/kg,对Mn2＋的吸附容量为95~5 594 mg/kg,对Ni2＋的吸附容量为158~6 213 mg/kg,对Zn2＋的吸附容量为151~6 710 mg/kg,对酸的中和容量为4.5~8.9 mol H＋/kg。工业废渣尤其是钢渣和赤泥在改善地下水酸性和去除矿业或工业废水中的重金属离子和酸性方面具有很好的应用前景,可以达到以废治废的目的。