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A method for recovering the three-dimensional structure of moving rigid and jointed objects from several single camera views is presented. The method is based on the fixed axis assumption: all movement consists of translations and rotations about an axis that is fixed in direction for short periods of time. This assumption makes it possible to recover the structure of any group of two or more rigidly connected points. The structure of jointed objects is recovered by analyzing them as collections of rigid parts, and then unifying the structures proposed for the parts. The method presented here has been tested on several sets of data, including movies used to demonstrate human perception of structure from motion.  相似文献   
103.
Pure cellulose was converted to oil by direct thermochemical aqueous-phase liquefaction. A model for yields from conversion was determined by regression of data from autoclave experiments. The conditions for optimum yield were found to be 315 °C, using 0.9 g equivalents/l of carbonate ion, and CO at 1.72 MPa (gauge pressure). Temperature had the most significant effect on yield. Analysis of the cellulose-derived product indicated a much larger fraction of aromatic carbon than had been thought possible previously. Compared to petroleum crude oil, the cellulose-derived oil had a greater fraction of high-molecular-weight components, a greater distillation residuum, greater viscosity, and greater oxygen content. Distillates of the cellulose-derived oil also contained significantly more oxygen than petroleum, but could potentially replace kerosene or related fuels.  相似文献   
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The heterogeneous integration of InSb quantum well transistors onto silicon substrates is investigated for the first time. 85 nm gate length FETs with fT = 305 GHz at Vds = 0.5 V and DC performance suitable for digital logic are demonstrated on material with a buffer just 1.8 mum thick. An initial step towards integrating InSb FETs with mainstream Si CMOS for high-speed energy-efficient logic applications has been achieved.  相似文献   
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Background

Biomonitoring is used in exposure and risk assessments to reduce uncertainties along the source-to-outcome continuum. Specifically, biomarkers can help identify exposure sources, routes, and distributions, and reflect kinetic and dynamic processes following exposure events. A variety of computational models now utilize biomarkers to better understand exposures at the population, individual, and sub-individual (target) levels. However, guidance is needed to clarify biomonitoring use given available measurements and models.

Objective

This article presents a biomonitoring research framework designed to improve biomarker use and interpretation in support of exposure and risk assessments.

Discussion

The biomonitoring research framework is based on a modified source-to-outcome continuum. Five tiers of biomonitoring analyses are included in the framework, beginning with simple cross-sectional and longitudinal analyses, and ending with complex analyses using various empirical and mechanistic models. Measurements and model requirements of each tier are given, as well as considerations to enhance analyses. Simple theoretical examples are also given to demonstrate applications of the framework for observational exposure studies.

Conclusion

This biomonitoring framework can be used as a guide for interpreting existing biomarker data, designing new studies to answer specific exposure- and risk-based questions, and integrating knowledge across scientific disciplines to better address human health risks.  相似文献   
108.
Ring-opening hydrolysis of epoxidized soybean oil in the presence of phosphoric acid was studied under varying experimental conditions. The influence of type and amount of solvents, phosphoric acid content and water content on the rate of ring-opening reactions and the characteristics of the derived products were studied. The soy-polyols prepared were characterized by determination of hydroxyl content, viscosity measurements, determination of average molecular weight and polydispersity index (GPC). The structural confirmation was done by FT-IR and 1H-NMR spectroscopy. The study shows that under the reaction conditions employed, a substantial degree of oligomerization due to oxirane-oxirane, and/or oxirane-hydroxyl reaction takes place. It is possible to synthesize soy-polyols having varying hydroxyl content and phosphate-ester functionality by controlling the type and amount of polar solvent and phosphoric acid content.  相似文献   
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