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This is the concluding part of a short introduction to multipulse NMR. The product operator formalism considered in Parts I and II (Concepts Magn. Reson., 1996, 8, 17-32; 1997, 9,117-137) is applied to the description of the INADE...
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This is the concluding part of a short introduction to multipulse NMR. The product operator formalism considered in Parts I and II (Concepts Magn. Reson., 1996, 8, 17-32; 1997, 9,117-137) is applied to the description of the INADEOUATE (incredible natural-abundance double-quantum experiment) pulse sequence. The basic one-dimensional INADEQUATE pulse technique, two-dimensional and selective modifications of this method, and the INADEQUATE with composite-refocusing pulse train are discussed.
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Due to inadequate data support, existing algorithms used to estimate soil hydraulic conductivity, K, in (eco)hydrological models ignore the effects of key site factors such as land use and climate and underplay the significant eff...
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Due to inadequate data support, existing algorithms used to estimate soil hydraulic conductivity, K, in (eco)hydrological models ignore the effects of key site factors such as land use and climate and underplay the significant effects of soil structure on water flow at and near saturation.These limitations may introduce serious bias and error into predictions of terrestrial water balances and soil moisture status, and thus plant growth and rates of biogeochemical processes. To resolve these issues, we collated a new global database of hydraulic conductivity measured by tension infiltrometer under field conditions. The results of our analyses on this data set contrast markedly with those of existing algorithms used to estimate K. For example, saturated hydraulic conductivity, Ks, in the topsoil (<0.3m depth) was found to be only weakly related to texture. Instead, the data suggests that Ks depends more strongly on bulk density, organic carbon content and land use. In this respect, organic carbon was negatively correlated with Ks, presumably due to water repellency, while Ks at arable sites was, on average, ca.2-3 times smaller than under natural vegetation, forests and perennial agriculture. The data also clearly demonstrates that clay soils have smaller K in the soil matrix and thus a larger contribution of soil macropores to K at and near saturation.
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Despite improvement over the last decade, inadequate method verification strategies and documentation are still common laboratory inspection deficiencies. Some of the gaps occur because microbiologists may not use scientific exper...
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Despite improvement over the last decade, inadequate method verification strategies and documentation are still common laboratory inspection deficiencies. Some of the gaps occur because microbiologists may not use scientific experiment concepts, such as experimental design, data validation, biostatistics, and electronic documentation, that can improve their verification strategies for new test methods. Other gaps occur because laboratory resources are often limited. Clinical laboratories face tough choices when they consider implementing a new test method, and this review summarizes the basic statistical concepts that microbiologists need to critically plan and review qualitative method verification with the aim of determining whether a new diagnostic test is fit for patient testing.
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Despite improvement over the last decade, inadequate method verification strategies and documentation are still common laboratory inspection deficiencies. Some of the gaps occur because microbiologists may not use scientific exper...
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Despite improvement over the last decade, inadequate method verification strategies and documentation are still common laboratory inspection deficiencies. Some of the gaps occur because microbiologists may not use scientific experiment concepts, such as experimental design, data validation, biostatistics, and electronic documentation, that can improve their verification strategies for new test methods. Other gaps occur because laboratory resources are often limited. Clinical laboratories face tough choices when they consider implementing a new test method, and this review summarizes the basic statistical concepts that microbiologists need to critically plan and review qualitative method verification with the aim of determining whether a new diagnostic test is fit for patient testing.
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The classic Weyl-van der Pol (WVDP) formula is a well-known asymptotic solution for accurately predicting sound fields above a locally reacting ground surface. However, the form of the WVDP formula is inadequate for predicting sou...
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The classic Weyl-van der Pol (WVDP) formula is a well-known asymptotic solution for accurately predicting sound fields above a locally reacting ground surface. However, the form of the WVDP formula is inadequate for predicting sound fields in the vicinity of non-locally reacting surfaces; a correction term is often required in the formula to provide accurate numerical solutions. Even with this correction, there is a singularity in the diffraction wave term when the source is located directly above or below the receiver. This paper explores a heuristic method to remove this singularity and suggests an analytical form comparable to the WVDP formula. This improved formula offers a physically interpretable solution and allows for accurate predictions of the total sound field above locally and non-locally reacting surfaces for all geometrical configurations.
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Because can be a really useful word in an A-level unit test. Add it to a response becomes worth a mark. Use it sloppily though, perhaps when 'and' might have been more appropriate, and you may fail to gain credit. With these point...
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Because can be a really useful word in an A-level unit test. Add it to a response becomes worth a mark. Use it sloppily though, perhaps when 'and' might have been more appropriate, and you may fail to gain credit. With these points in mind, this Upgrade concentrates on just one word -- because.
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Acommon lab exercise in the introductory college physics course employs a low-friction cart and associated track to study the validity of Newton's second law. Yet for college students, especially those who have already encountered...
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Acommon lab exercise in the introductory college physics course employs a low-friction cart and associated track to study the validity of Newton's second law. Yet for college students, especially those who have already encountered a good high school physics course, the exercise must seem a little pointless. These students have already learned to accept Newton's laws without question, and any experimental data that contradict the second law would immediately alert students to an error in procedure or analysis, or, worse, reinforce the widely held opinion that simple laws are inadequate to explain the behavior of "real" systems. A better approach is to ask students to apply their understanding of Newton's laws to determine one or more unknowns inherent in the laboratory apparatus. We illustrate this approach in the experiment described below: a small amount of complexity is added to a standard experimental exercise, forcing a careful analysis of the collected data and yielding very accurate results plus a thorough understanding of the physical system under study. If development of experimental skills is one of the primary goals of the introductory laboratory, then the strategy illustrated below might be widely adaptable and appropriate in laboratories throughout the introductory mechanics curriculum
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In Nepal, 26%-38% of recent births are estimated to be from unintended pregnancies, but little is known whether these pregnancies have adverse consequences for the health of the mother and child. Data from the 2011 Nepal Demograph...
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In Nepal, 26%-38% of recent births are estimated to be from unintended pregnancies, but little is known whether these pregnancies have adverse consequences for the health of the mother and child. Data from the 2011 Nepal Demographic and Health Survey are used to examine the hypothesis that unintended pregnancies are associated with negative health outcomes for both mothers and children. When the pregnancy was unintended (compared with when it was intended) mothers were more likely to receive inadequate prenatal care (odds ratio OR = 1.50; 95% confidence interval [CI] = 1.28-1.77). They were also more likely to opt for home births (OR = 1.30; 95% CI = 1.11-1.52). Likewise, the resultant newborns of unintended pregnancies were more likely to receive inadequate immunization (OR = 1.18; 95% CI = 1.00-1.40) and to remain stunted (OR = 1.25; 95% CI = 1.00-1.56). Findings suggest significant associations between unintended pregnancy and negative health outcomes for both mothers and children in Nepal.
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Inadequate management cause soil degradation increasing runoff surface. This work was performed in the sub-basin river Jardim Novo Horizonte, located in the municipality of IlhaSolteira, northwest of S?o Paulo. This region present...
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Inadequate management cause soil degradation increasing runoff surface. This work was performed in the sub-basin river Jardim Novo Horizonte, located in the municipality of IlhaSolteira, northwest of S?o Paulo. This region presents environmental problems such as soil erosion and siltation of rivers. This study aimed to estimate the runoff surface of soil sub-basin river Jardim Novo Horizonte. The soils of the sub-basin river are the Oxisol and Alfisol, both of medium texture. The runoff simulation was performed using the computer program SIMHUNER, using daily data of precipitation, evapotranspiration and outflow from August 1991 to August 2009. For the simulation we used data of precipitation and evapotranspiration of the Municipality of Ilha Solteira, SP. The flow data were estimated using the method of curve-number. The low values of runoff coefficient observed indicates that only a small part of the precipitation that arrives on the sub-basin river is converted into runoff, meaning that it has a low tendency to runoff if properly managed.
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In many situations in contemporary science and engineering, the analysis and prediction of crucial phenomena occur often through complex dynamical equations that have significant model errors compared with the true signal in natur...
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In many situations in contemporary science and engineering, the analysis and prediction of crucial phenomena occur often through complex dynamical equations that have significant model errors compared with the true signal in nature. Here, a systematic information theoretic framework is developed to improve model fidelity and sensitivity for complex systems including perturbation formulas and multimodel ensembles that can be utilized to improve both aspects of model error simultaneously. A suite of unambiguous test models is utilized to demonstrate facets of the proposed framework. These results include simple examples of imperfect models with perfect equilibrium statistical fidelity where there are intrinsic natural barriers to improving imperfect model sensitivity. Linear stochastic models with multiple spatiotemporal scales are utilized to demonstrate this information theoretic approach to equilibrium sensitivity, the role of increasing spatial resolution in the information metric for model error, and the ability of imperfect models to capture the true sensitivity. Finally, an instructive statistically nonlinear model with many degrees of freedom, mimicking the observed non-Gaussian statistical behavior of tracers in the atmosphere, with corresponding imperfect eddy-diffusivity parameterization models are utilized here. They demonstrate the important role of additional stochastic forcing of imperfect models in order to systematically improve the information theoretic measures of fidelity and sensitivity developed here.
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