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741.
Closed-tube pyrolysis of 2,4,6-tribromoaniline (TBAn) produced polybromophenazines (PBPZs). The identities of these compounds were supported by matching their mass spectra with the mass spectra of brominated phenazines and by the formation of phenazine from the pyrolysis of aniline under the same conditions. Tetrabromophenazine (T4BPZ) was isolated from the pyrolysis by-products by using activated acid alumina column. An study showed that T4BPZ exhibits dioxin-like activity.  相似文献   
742.
Droplet size distribution inside water flashing jets and corresponding rain-out fraction were measured. Mass distribution showed that a few droplets are ‘large’ (d>150 μm) and count for more than 85% of the liquid mass in the jet because of their large individual mass. This could be due to incomplete thermal fragmentation. It could explain the rain-out falling near the orifice or pipe exit.  相似文献   
743.
Despite several recent UK initiatives to promote renewable energy development at the local level, little research has been carried out to investigate public beliefs about aspects of local renewable energy development. This research attempted to address this gap. Empirical data were collected at the Awel Aman Tawe development in South Wales immediately before and after a public participation process. The results indicate that support for specific aspects of local energy development (partnership with local communities, local use of generated energy and profits put back into the local community) was consistently high across time, with support for local ownership at a slightly lower level, yet still high. Secondly, socio-demographical analyses indicated that personal factors such as respondents' age, gender and employment status were important in shaping several of these beliefs. Since UK renewable energy development has often been controversial and subject to delay, results suggest that the adoption of a locally embedded development approach by public and private sector stakeholders will be strongly supported by local people. The implications of the results are discussed in relation to existing industry best practice guidelines and recent policy initiatives.  相似文献   
744.
745.
ABSTRACT: The predominant mixtures of pesticides found in New York surface waters consist of five principal components. First, herbicides commonly used on corn (atrazine, metolachlor, alachlor, cyanazine) and a herbicide degradate (deethylatrazine) were positively correlated to a corn‐herbicide component, and watersheds with the highest corn‐herbicide component scores were those in which large amounts of row crops are grown. Second, two insecticides (diazinon and carbaryl) and one herbicide (prometon) widely used in urban and residential settings were positively correlated to an urban/residential component. Watersheds with the highest urban/residential component scores were those with large amounts of urban and residential land use. A third component was related to two herbicides (EPTC and cyanazine) used on dry beans and corn, the fourth to an herbicide (simazine) and an insecticide (carbaryl) commonly used in orchards and vineyards, and the fifth to an herbicide (DCPA). Results of this study indicate that this approach can be used to: (1) identify common mixtures of pesticides in surface waters, (2) relate these mixtures to land use and pesticide applications, and (3) indicate regions where these mixtures of pesticides are commonly found.  相似文献   
746.
ABSTRACT: Nine surface water‐quality variables were analyzed for trend at 180 Virginia locations over the 1978 to 1995 period. Median values and seasonal Kendall's tau, a trend indicator statistic, were generated for dissolved oxygen saturation (DO), biochemical oxygen demand (BOD), pH (PH), total residue (TR), nonfilterable residue (NFR), nitrate‐nitrite nitrogen (NN), total Kjeldahl nitrogen (TKN), total phosphorus (TP), and fecal coliform (FC) at each location. Each location was assigned to one of four physiographic regions, and mean state and regional medians and taus were calculated. Widespread BOD and NFR improvements were detected and FC improvements occurred in the state's western regions. TR and TKN exhibited predominantly increasing trends at locations throughout the state. BOD, TKN, NFR, and TR medians were higher at coastal locations than in other regions. NN, TKN, and TR exhibited predominantly increasing trends in regions with high median concentrations, while declining trends predominated in regions with relatively high BOD, FC, and NFR medians. Appalachian locations exhibited the greatest regional water‐quality improvements for BOD, FC, NFR, and TKN. Factors responsible for regional differences appear to include geology, land use, and landscape features; these factors vary regionally.  相似文献   
747.
Pericentric inversion of the human Y chromosome has been estimated to occur with a frequency of 1–2 per thousand in various populations, and the results of this study, derived from over 12 000 prenatal diagnosis cases, is 1.15 per 1000. In these cases, it was concluded that there was no clinical significance because the fathers and male fetuses had the same pericentric inversion. Chromosome analysis of the father is advisable to determine whether or not the inversion is familial in order to be able to provide genetic counselling.  相似文献   
748.
The purpose of this note is to review Prudencio's recent experimental test of the Coasian propositions of neutrality and efficiency. His conclusion that the propositions are statistically supported by the experimental results is not substantiated. A careful examination of the design and methodology of the experiment leads to the conclusion that the experimental bargaining cannot be considered voluntary, and that the results are likely to be influenced by hypothetical bias. Other problems with the representativeness of Prudencio's participants are also discussed.  相似文献   
749.
The Marfan syndrome (MFS) is a heritable connective tissue disorder characterized by skeletal, ocular, and cardiovascular abnormalities. Defects in fibrillin, an elastin-associated microfibrillar protein, are now known to cause MFS. Since the discovery of fibrillin as the gene responsible for MFS, requests for prenatal and presymptomatic diagnosis have become common-place. Here we report the use of the polymerase chain reaction (PCR), using fluorescence labelled primers and an automated sequencer, to establish linkage data for “molecular diagnosis”. The mistaken clinical diagnosis of MFS based on the appearance of a common cardiovascular manifestation, mitral valve prolapse, and a positive family history is also discussed.  相似文献   
750.
本文研究了米达河(南纬3°20',东经40°00')两个红树林森林地区(乌永博和基雷普维)带状横断面的红树林植被的结构和恢复型式.  相似文献   
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