In the multifactorial preparation of porous materials, the simultaneous/se<span style="white-space:normal;font-size:10pt;font-family:;" "="">- </span><span style="white-spa...In the multifactorial preparation of porous materials, the simultaneous/se<span style="white-space:normal;font-size:10pt;font-family:;" "="">- </span><span style="white-space:normal;font-size:10pt;font-family:;" "="">quential influence of a number of technological variables changes the individual parameters of the texture of the material (surface area, volume, pore size, etc.) to different values and with increase or decrease. Generalized parameters (GPs) combine these changes;new dependencies arise. GPs behave like the dimensionless similarity numbers known in science and technology (Reynolds, etc</span><span style="white-space:normal;font-size:10pt;font-family:;" "="">.</span><span style="white-space:normal;font-size:10pt;font-family:;" "="">). They split the data (phenomena) into series with similar properties, reveal special patterns and structural nuances. New GPs proposed. The average pore size is presented as the product of two GPs: the <i>dimentionless</i> shape factor F and pore width of <i>unknown</i> shape (reciprocal of the volumetric surface). Using F, for example, the SBA-15 dataset (D. Zhao, Science 1998) was split into 3 series of samples differing in synthesis temperatures, unit cell parameters, intra-wall pore volumes, pore lengths, and the ratios of wall thickness to pore size. A surprising phenomenon was discovered one of the copolymers acts in a similar way to high temperatures.</span><span style="white-space:normal;font-size:10pt;font-family:;" "=""> </span><span style="white-space:normal;font-size:10pt;font-family:;" "="">The standard deviation (STD, %) of the texture parameter in the series is its <i>serial</i> GP. The surface topography (micropore volume per m<sup>2</sup>) is proposed;it eliminates fluctuation in material density and has a lower STD than cm<sup>3</sup>/g. Examples of the use of GPs for silica, carbon, alumina and catalysts are given. A correlation has been shown between the efficiency of some catalytic reactions (adsorption) and GPs.</span><span style="white-space:normal;展开更多
Introduction:Estimating surface temperature from above-ground field measurements is important for understanding the complex landscape patterns of plant seedling survival and establishment,processes which occur at heig...Introduction:Estimating surface temperature from above-ground field measurements is important for understanding the complex landscape patterns of plant seedling survival and establishment,processes which occur at heights of only several centimeters.Currently,future climate models predict temperature at 2 m above ground,leaving ground-surface microclimate not well characterized.Methods:Using a network of field temperature sensors and climate models,a ground-surface temperature method was used to estimate microclimate variability of minimum and maximum temperature.Temperature lapse rates were derived from field temperature sensors and distributed across the landscape capturing differences in solar radiation and cold air drainages modeled at a 30-m spatial resolution.Results:The surface temperature estimation method used for this analysis successfully estimated minimum surface temperatures on north-facing,south-facing,valley,and ridgeline topographic settings,and when compared to measured temperatures yielded an R2 of 0.88,0.80,0.88,and 0.80,respectively.Maximum surface temperatures generally had slightly more spatial variability than minimum surface temperatures,resulting in R2 values of 0.86,0.77,0.72,and 0.79 for north-facing,south-facing,valley,and ridgeline topographic settings.Quasi-Poisson regressions predicting recruitment of Quercus kelloggii(black oak)seedlings from temperature variables were significantly improved using these estimates of surface temperature compared to air temperature modeled at 2 m.Conclusion:Predicting minimum and maximum ground-surface temperatures using a downscaled climate model coupled with temperature lapse rates estimated from field measurements provides a method for modeling temperature effects on plant recruitment.Such methods could be applied to improve projections of species’range shifts under climate change.Areas of complex topography can provide intricate microclimates that may allow species to redistribute locally as climate changes.展开更多
Based on analyzing various factors influencing milled surface topography, firstly, a generalized model for milled surface topography is proposed. Secondly, using the principles of transformation matrix and vector oper...Based on analyzing various factors influencing milled surface topography, firstly, a generalized model for milled surface topography is proposed. Secondly, using the principles of transformation matrix and vector operation, the trajectory equation of cutting edge relative to workpiece is derived. Then, a three dimensional topography simulation algorithm is constructed through dividing the workpiece into regular grids. Finally, taking the peripheral milling process as an example, the generalized model is simplified, and the corresponding simulation examples are given. The results indicate that it is very efficient for the generalized model to be used to analyze and simulate the peripherally milled surface topography.展开更多
By using a weakly nonlinear and perturbation method, the generalized inhomogeneous Korteweg de Vries （KdV）- Burgers equation is derived, which governs the evolution of the amplitude of Rossby waves under the influen...By using a weakly nonlinear and perturbation method, the generalized inhomogeneous Korteweg de Vries （KdV）- Burgers equation is derived, which governs the evolution of the amplitude of Rossby waves under the influence of dissipation and slowly varying topography with time. The analysis indicates that dissipation and slowly varying topography with time are important factors in causing variation in the mass and energy of solitary waves.展开更多
文摘In the multifactorial preparation of porous materials, the simultaneous/se<span style="white-space:normal;font-size:10pt;font-family:;" "="">- </span><span style="white-space:normal;font-size:10pt;font-family:;" "="">quential influence of a number of technological variables changes the individual parameters of the texture of the material (surface area, volume, pore size, etc.) to different values and with increase or decrease. Generalized parameters (GPs) combine these changes;new dependencies arise. GPs behave like the dimensionless similarity numbers known in science and technology (Reynolds, etc</span><span style="white-space:normal;font-size:10pt;font-family:;" "="">.</span><span style="white-space:normal;font-size:10pt;font-family:;" "="">). They split the data (phenomena) into series with similar properties, reveal special patterns and structural nuances. New GPs proposed. The average pore size is presented as the product of two GPs: the <i>dimentionless</i> shape factor F and pore width of <i>unknown</i> shape (reciprocal of the volumetric surface). Using F, for example, the SBA-15 dataset (D. Zhao, Science 1998) was split into 3 series of samples differing in synthesis temperatures, unit cell parameters, intra-wall pore volumes, pore lengths, and the ratios of wall thickness to pore size. A surprising phenomenon was discovered one of the copolymers acts in a similar way to high temperatures.</span><span style="white-space:normal;font-size:10pt;font-family:;" "=""> </span><span style="white-space:normal;font-size:10pt;font-family:;" "="">The standard deviation (STD, %) of the texture parameter in the series is its <i>serial</i> GP. The surface topography (micropore volume per m<sup>2</sup>) is proposed;it eliminates fluctuation in material density and has a lower STD than cm<sup>3</sup>/g. Examples of the use of GPs for silica, carbon, alumina and catalysts are given. A correlation has been shown between the efficiency of some catalytic reactions (adsorption) and GPs.</span><span style="white-space:normal;
基金We gratefully acknowledge funding support from the National Science Foundation Macrosystems Biology Program,NSF#EF-1065864,and thank our collaborating investigators(A.Hall,L.Hannah,M.Moritz,M.North,K.Redmond,H.Regan,A.Syphard).The manuscript was improved by comments from H.Regan.S.McKnight and A.Shepard coordinated field site set-up,while E.Conlisk,S.Dashiell,L.di Scipio,E.Hopkins,A.MacDonald,K.Maher,J.McClure,P.Prather,E.Peck,R.Swab,and W.Wilkinson contributed to data collection and maintenance of the common gardens and field sensors.We thank the USDA Forest Service and Tejon Ranch Company for access to field sites.P.Slaughter has been instrumental with development of the field data processing system and database ingest software.Lastly,we would like to thank The Earth Research Institute staff at UC Santa Barbara for their assistance and support.
文摘Introduction:Estimating surface temperature from above-ground field measurements is important for understanding the complex landscape patterns of plant seedling survival and establishment,processes which occur at heights of only several centimeters.Currently,future climate models predict temperature at 2 m above ground,leaving ground-surface microclimate not well characterized.Methods:Using a network of field temperature sensors and climate models,a ground-surface temperature method was used to estimate microclimate variability of minimum and maximum temperature.Temperature lapse rates were derived from field temperature sensors and distributed across the landscape capturing differences in solar radiation and cold air drainages modeled at a 30-m spatial resolution.Results:The surface temperature estimation method used for this analysis successfully estimated minimum surface temperatures on north-facing,south-facing,valley,and ridgeline topographic settings,and when compared to measured temperatures yielded an R2 of 0.88,0.80,0.88,and 0.80,respectively.Maximum surface temperatures generally had slightly more spatial variability than minimum surface temperatures,resulting in R2 values of 0.86,0.77,0.72,and 0.79 for north-facing,south-facing,valley,and ridgeline topographic settings.Quasi-Poisson regressions predicting recruitment of Quercus kelloggii(black oak)seedlings from temperature variables were significantly improved using these estimates of surface temperature compared to air temperature modeled at 2 m.Conclusion:Predicting minimum and maximum ground-surface temperatures using a downscaled climate model coupled with temperature lapse rates estimated from field measurements provides a method for modeling temperature effects on plant recruitment.Such methods could be applied to improve projections of species’range shifts under climate change.Areas of complex topography can provide intricate microclimates that may allow species to redistribute locally as climate changes.
文摘Based on analyzing various factors influencing milled surface topography, firstly, a generalized model for milled surface topography is proposed. Secondly, using the principles of transformation matrix and vector operation, the trajectory equation of cutting edge relative to workpiece is derived. Then, a three dimensional topography simulation algorithm is constructed through dividing the workpiece into regular grids. Finally, taking the peripheral milling process as an example, the generalized model is simplified, and the corresponding simulation examples are given. The results indicate that it is very efficient for the generalized model to be used to analyze and simulate the peripherally milled surface topography.
基金supported by the Knowledge Innovation Key Program of the Chinese Academy of Sciences (Grant No. KZCX1-YW-12)the National Key Science Foundation of China (Grant No. 41030855)
文摘By using a weakly nonlinear and perturbation method, the generalized inhomogeneous Korteweg de Vries （KdV）- Burgers equation is derived, which governs the evolution of the amplitude of Rossby waves under the influence of dissipation and slowly varying topography with time. The analysis indicates that dissipation and slowly varying topography with time are important factors in causing variation in the mass and energy of solitary waves.
