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1.
We report on compound formation in the system HgCdTeO. Samples were prepared by solid state reaction of mixtures of the binary oxide components. Specific phases were identified and characterized by X-ray and microprobe techniques. For some of these compounds small single crystals could be prepared and structural data of which are reported. Three groups of phases could be distinguished, most of them being of low symmetry, with Te in +4, +6, and in mixed oxidation states. The monotellurites HgTeO3 and CdTeO3 are structurally different and exhibit a large miscibility gap, whereas for the di-tellurites complete solid solution between CdTe2O5 and HgTe2O5 was found. As to the tellurates, phases with the compositions MTeO4 and M3Te2O9 (M = Hg, Cd) have been prepared. The Cd3Te2O9-structure is stabilized by 30 mole% Hg. Another tellurate, monoclinic Hg2TeO4, was found to be isomorphous to the respective selenate and sulfate and is identical with the mineral magnolite. The interaction of Te2O5 with the metal oxides led to the formation of mixed valence compounds with both Te(+4) and Te(+6) of the types M2Te2O7 and MTe2O6. 相似文献
2.
A. I. Ageev I. V. Bogdanov V. V. Zubko S. S. Kozub P. I. Slabodchikov V. V. Sytnik L. M. Tkachenko P. A. Shcherbakov K. Blachet J. Cauhertz G. Moritz 《Atomic Energy》2002,93(6):957-960
The superconducting dipoles developed as part of the UNK project have reached a magnetic field 6 T at a rate of up to 0.8 T/sec. Experimental data are presented on the conditioning, rate dependences, and dynamic losses for magnets with two types of superconducting cable (zebra and oxide). Possible ways to decrease the heat release in a dipole operating in rapid-cycling magnetic fields are examined. The results of an analysis of heat release and temperature conditions are presented for a dipole with a winding made of improved current-carrying components. 相似文献
3.
We analyzed the first 5 years of surveillance data from the Established Population for the Epidemiologic Studies of the Elderly (EPESE) in the Piedmont of North Carolina (n = 4162) to estimate the effect of a global self-rating of health on survival. Covariates used in Cox proportional hazard models included sociodemographic factors, chronic medical conditions, activities of daily living, use of health services, health risk behaviors, cognitive function, affective mood, and negative life events. Adjusted risk of mortality associated with poor (compared to excellent) self-ratings of health was significantly elevated among urban men only. Confounders of the association between survival and overall health assessment varied widely by subgroup. Pooled estimates from heterogeneous populations may mask significant subgroup differences both in the pattern of variables that mediate crude risk and also in the magnitude of residual risk of global self-ratings of health. 相似文献
4.
5.
ML McLaws C Murphy P Taylor M Ferson J Gold R Donnellan D Dalton 《Canadian Metallurgical Quarterly》1997,18(11):778-780
The rate of nosocomial respiratory syncytial virus (RSV) infection was measured in a large pediatric hospital using an incidence density method. The at-risk days for nosocomial RSV were summed during a defined winter period in which there were 54 admissions with community-acquired RSV infection giving a rate of 2.9 cases per 1,000 at-risk days (95% confidence interval, 0.3-5.4 per 1,000). 相似文献
6.
M Karlberg M Magnusson EM Malmstr?m A Melander U Moritz 《Canadian Metallurgical Quarterly》1996,77(9):874-882
OBJECTIVE: To assess postural performance in patients with dizziness of suspected cervical origin in whom extracervical causes had been excluded, and to assess the effects of physiotherapy on postural performance and subjective complaints of neck pain and dizziness. DESIGN: Prospective, randomized, controlled trial. SETTING: Primary care centers and a tertiary referral center. PATIENTS AND SUBJECTS: Of 65 referrals, 43 patients were excluded because extracervical etiology was suspected. Of the remaining 22 patients, 17 completed the study (15 women, 2 men, x age 37 yr, range 26-49). The controls were 17 healthy subjects (15 women, 2 men, x age 36 yr, range 25-55). INTERVENTION: Physiotherapy based on analysis of symptoms and findings, and aimed to reduce cervical discomfort. Patients were randomized either to receive immediate physiotherapy (n = 9), or to wait 2 months, undergo repeat measurements, and then receive physiotherapy (n = 8). MAIN OUTCOME MEASURES: Posturography, measuring velocity and variance of vibration-induced body sway and variance of galvanically induced body sway. Subjective intensity of neck pain (Visual Analog Scale ratings, 0-100), intensity and frequency of dizziness (subjective score 0-4). RESULTS: The patients manifested significantly poorer postural performance than did healthy subjects (.05 > p > .0001). Physiotherapy significantly reduced neck pain and intensity and the frequency of dizziness (p < .01), and significantly improved postural performance (.05 > p > .0007). CONCLUSIONS: Patients with dizziness of suspected cervical origin are characterized by impaired postural performance. Physiotherapy reduces neck pain and dizziness and improves postural performance. Neck disorders should be considered when assessing patients complaining of dizziness, but alternative diagnoses are common. 相似文献
7.
8.
As a response to attack by herbivores, plants can emit a variety of volatile substances that attract natural enemies of these insect pests. Predators of the banana weevil, Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) such as Dactylosternum abdominale (Coleoptera: Hydrophilidae) and Pheidole megacephala (Hymenoptera: Formicidae), are normally found in association with weevil-infested rotten pseudostems and harvested stumps. We investigated whether these predators are attracted to such environments in response to volatiles produced by the host plant, by the weevil, or by the weevil–plant complex. We evaluated predator responses towards volatiles from banana pseudostem tissue (synomones) and the synthetic banana weevil aggregation pheromone Cosmolure+ in a two-choice olfactometer. The beetle D. abdominale was attracted to fermenting banana pseudostem tissue and Cosmolure+, whereas the ant P. megacephala was attracted only to fermented pseudostem tissue. Both predators were attracted to banana pseudostem tissue that had been damaged by weevil larvae irrespective of weevil presence. Adding pheromone did not enhance predator response to volatiles from pseudostem tissue fed on by weevils. The numbers of both predators recovered with pseudostem traps in the field from banana mats with a pheromone trap were similar to those in pseudostem traps at different distance ranges from the pheromone. Our study shows that the generalist predators D. abdominale and P. megacephala use volatiles from fermented banana pseudostem tissue as the major chemical cue when searching for prey. 相似文献
9.
Bioconversion of sludge from the primary clarifier of a sulphite pulping operation to ethanol offers a number of advantages over conventional disposal options. The amount of material which must be disposed of is reduced while, at the same time, salable and environmentally friendly fuel-ethanol is produced. In this study, primary clarifier sludge (PCS) was shown to be hydrolysed to produce fermentable sugars at a rate proportional to enzyme loading. Initial (1 hour) hydrolysis rates as high as 12.6 g reducing sugar/L · h were observed at an initial enzyme loading of 10 filter paper units (FPU)/g. Hydrolysis was inhibited by spent sulphite liquor (SSL), an inhibition which could be completely overcome by fermenting the SSL to remove sugars. Surfactants were found to only marginally improve the production of sugars. To reduce the deleterious effects of end product inhibition, single stage simultaneous hydrolysis and fermentation (SHF) was carried out using cellulase enzymes and Saccharomyces cerevisiae. 相似文献
10.
H. H. J. L. Ploegmakers P. A. Moritz P. J. M. M. Toll W. J. van Oort 《Journal of Automated Methods and Management in Chemistry》1989,11(3):106-112
A computerized electrochemical detection system for application
after HPLC, provided with a cyclic voltammetric oxidative and
reductive module, is described for the on-line qualitative determination
of electroactive antineoplastic agents and metabolites in urine
samples, collected from cancer patients, following intravenous
administration.The application of two cyclic voltammetric detection modes
provides an insight into both oxidative and reductive electrode
reactions of compounds, passing the detector and the occurrence of
(it)reversible chemical and electrochemical processes at the electrode
surface. In this way, redox properties of drugs and metabolites
characteristic of their molecular structure, can be established, which
may provide information related to their (enzymatic) bioactivation.In the cyclic voltammetric mode, the system permits automatic
detection of a compound in the cell, recording, storage and plotting
of voltammograms and calculation of the retention times, the
half-wave potentials and the peak potentials of each scan of all
individual compounds. For routine use, storage of 68 voltammograms
on-line is sufficient for the analysis of biological samples in
clinical-pharmacological research. Special attention has been paid
to automatic, multi-reference-point component detection.Based on their concentrations in urine, the oxidative cyclic
voltammetric mode, using a glassy carbon electrode, permits the
determination of etoposide and teniposide, whereas the reductive
cyclic voltammetric mode, with a static mercury drop electrode,
permits the determination of adriamycin and its metabolite
adriamycinol. 相似文献