摘要:

The reactions of O3with acetylene, methylglyoxal and a series of aromatic hydrocarbons were studied at 297 ± 2°K. Rate constants k2were obtained from the O3decay rates in the presence of excess reactant and were determined to be (k2× 1020cm3molecule‐1sec‐1): acetylene 3.8 ± 0.6; methylglyoxal 0.11 ± 0.05; benzene 0.007 ± 0.004; toluene 0.015 ± 0.008; o‐xylene 0.07 ± 0.02; m‐xylene 0.06 ± 0.02; p‐xylene 0.04 ± 0.02; 1,2,3‐trimethylbenzene 0.16 + 0.04; 1,2,4‐trimethylbenzene 0.13 ± 0.03; 1,3,5‐trimethylbenzene 0.22 ± 0.06. The major products identified from the reaction of O3with toluene, o‐xylene and 1,3,5‐trimethylbenzene were α‐dicarbonyls.

ISSN:0360-1226    

DOI:10.1080/10934527609385750

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

Male melon flies,Dacus cucurbitaeCoquillett, treated with a single dose of the chemosterilant tepa (tris(l‐aziridinyl) phosphine oxide), or with gamma irradiation, either single or fractionated doses, did not differ significantly in sexual competitiveness as determined by percentage hatch of eggs. Mating competitiveness of males treated by either method ranged from 53 to 66% of that of untreated males. In another study, melon flies (males and females) sterilized with 0.0125% tepa, the threshold dose for both sexes, completely suppressed a population when the ratio was 16:16:1:1 (sterile males‐sterile females‐untreated males‐untreated females) as determined by no egg hatch.

ISSN:0360-1226    

DOI:10.1080/10934527609385751

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

Rate constants for the removal of peroxyacetyl nitrate (PAN) in the presence of SO2, isobutene, CO, CH3CHO, NO2, H2O, O3and NO were determined at 296 ± 1°K by monitoring the decay of PAN in excess reactant as a function of time by infrared absorption spectroscopy and/or gas chromatography. The second order rate constants observed were (ppm‐1min‐1): SO2< 2 × 10‐8; isobutene < 1 × 10‐6; CO < 2 × 10‐7; CH3CHO (1.1 ± 0.2) x 10‐6; N02(2.6 ± 1.2) × 10‐6; H2O (3.3 ± 0.5) x 10‐8; O3= 8 × 10‐5. These reactions with CH3CHO, NO2, and H2O are sufficiently slow so that heterogeneous removal processes for PAN cannot be excluded. For the reaction of PAN with NO, the initial rates of removal of PAN were observed to be first order in PAN concentration and independent of the NO concentration, with a first order rate constant of (1.7 ± 0.5) × 10‐2min‐1. Possible reaction mechanisms are discussed along with estimates of PAN half‐lives in polluted urban atmospheres.

ISSN:0360-1226    

DOI:10.1080/10934527609385752

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

The lead contents of several specimens of flora and fauna collected during 1971, 1972 and 1973 along the Pacific coast from Piedras Blancas, California to Punta Banda, Baja California were determined by isotope dilution method. These marine organisms, on a dry weight basis, contained from 0.014 to 15 parts per million of lead, which can be correlated to their local habitats.

ISSN:0360-1226    

DOI:10.1080/10934527609385753

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

A stationary source simulator facility has been developed and is in use by EPA personnel at the Environmental Science Research Laboratories, located in the Research Triangle Park, N. C. The facility, which is essentially a wind tunnel, is so designed as to allow the selection of a wide variety of stationary source emission characteristics. The tunnel is used in various research projects related to the development of measurement instrumentation for gases and particulate pollutants. The characteristics required for many research projects can be provided automatically with an accompanying computer.

ISSN:0360-1226    

DOI:10.1080/10934527609385754

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

The possibility of using the shells of various fresh water mollusks as indicators of lead levels has been investigated. Shells ofCorbicula manillensis(Asiatic clam) were found to be reliable and readily available indicators of lead levels. Samples collected at a relatively clean site were found to yield a mean lead concentration of 0.6 ppm with a range of .1 ‐ 1.3 ppm. The sample means from other sites were increased by factors between 2 and 3. Also, the shells from very young (less than one year old)C.manillensiscontained unusually high concentrations of lead.

ISSN:0360-1226    

DOI:10.1080/10934527609385755

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

An automated photometric end point detection of the Ba(C104)2titration of sulfate using thorin as an indicator is described. The technique has a detection limit of 1–2 μg of sulfate. Results of studies of end point, pH effect, and ionic strength or cation effect are given. Although ion exchange is usually unnecessary, it is described and studied. Comparisons are made between the photometric end point detection, visual end point detection, and microgravimetric sulfate determination.

ISSN:0360-1226    

DOI:10.1080/10934527609385756

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

ISSN:0360-1226    

DOI:10.1080/10934527609385757

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

The partition coefficients and solubilities of dimethylmercury in distilled and sea water over a temperature range 0–25°C, have been measured using a head‐space technique.

ISSN:0360-1226    

DOI:10.1080/10934527609385758

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor