Objective To investigate the feasibility and surgical effects of posterior articular process approach for the treatment of L1-L3 lumbar disc herniation.Methods A retrospective study,of17patients with upper lumbar inte...Objective To investigate the feasibility and surgical effects of posterior articular process approach for the treatment of L1-L3 lumbar disc herniation.Methods A retrospective study,of17patients with upper lumbar intervertebml disc展开更多
During smile evaluation and anterior esthetic construction,the anatomic and racial variations should be considered in order to achieve better matching results.The aims of this study were to validate an objective metho...During smile evaluation and anterior esthetic construction,the anatomic and racial variations should be considered in order to achieve better matching results.The aims of this study were to validate an objective method for recording spontaneous smile process and to categorize the smile and upper lip curvature of Chinese Han-nationality youth.One hundred and eighty-eight Chinese Han-nationality youths(88 males and 100 females) ranged from 20 to 35 years of age were selected.Spontaneous smiles were elicited by watching comical movies and the dynamics of the spontaneous smile were captured continuously with a digital video camera.All subjects’ smiles were categorized into three types:commissure,cuspid and gummy smile based on video editing software and final images.Subjects’ upper lip curvatures were also measured and divided into three groups:upward,straight and downward.Reliability analysis was conducted to obtain intra-rater reliabilities on twice measurements.The Pearson Chi-square test was used to compare differences for each parameters(α=0.05).In smile classification,60.6%commissure smile,33.5%cuspid smile and 5.9%gummy smile were obtained.In upper lip measurement,26.1%upward,39.9%straight and 34.0%downward upper lip curvature were determined.The commissure smile group showed statistically significant higher percentage of straight(46.5%) and upward(40.4%) in upper lip curvatures(P<0.05),while cuspid smile group(65.1%) and gummy smile group(72.7%) showed statistically significant higher frequency in downward upper lip curvature(P<0.05).It is evident that differences in upper lip curvature and smile classification exist based on race,when comparing Chinese subjects with those of Caucasian descent,and gender.展开更多
We present a three-level nested-grid ocean circulation modeling system for the Belize shelf of the western Caribbean Sea. The nested-grid system has three subcomponents： a coarse-resolution outer model of the western...We present a three-level nested-grid ocean circulation modeling system for the Belize shelf of the western Caribbean Sea. The nested-grid system has three subcomponents： a coarse-resolution outer model of the western Caribbean Sea; an intermediate-resolution middle model of the southern Mest〉American Barrier Reef System; and a fine-resolution inner model of the Belize shelf. The two-way nesting technique based on the semi-prognostic method is used to exchange information between the three subcomponents. We discuss two applications of the nested-grid system in this study. In the first application we simulate the seasonal mean circulation in the region, with the nested system forced by monthly mean surface fluxes and boundary forcing. The model results reproduce the general circulation features on the western Caribbean Sea and mest〉scale circulation features on the Belize shelf. In the second application, we simulate the storm-induced circulation during Hurricane Mitch in 1998, with the nested-grid system forced by the combination of monthly mean forcing and idealized wind stress associated with the storm. The model results demonstrate that the storm-induced currents transport a large amount of estuarine waters from coastal regions of Honduras and Guatemala to offshore reef atolls.展开更多
Wave-wave interactions cause energy cascades. These are the most important processes in the upper ocean because they govern wave-growth and dissipation. Through indirect cascades, wave en- ergy is transferred from hig...Wave-wave interactions cause energy cascades. These are the most important processes in the upper ocean because they govern wave-growth and dissipation. Through indirect cascades, wave en- ergy is transferred from higher frequencies to lower frequencies, leading to wave growth. In direct cas- cades, energy is transferred from lower frequencies to the higher frequencies, which causes waves to break, and dissipation of wave energy. However, the evolution and origin of energy cascade processes are still not fully understood. In particular, for example, results from a recent theory (Kalmykov, 1998) sug- gest that the class I wave-wave interactions (defined by situations involving 4-, 6-, 8-, etc, even numbers of resonantly interacting waves) cause indirect cascades, and Class II wave-wave interactions (involving, 5-, 7-, 9-, etc, .., odd numbers of waves) cause direct cascades. In contrast to this theory, our model results indicate the 4-wave interactions can cause significant transfer of wave energy through both direct and in- direct cascades. In most situations, 4-wave interactions provide the major source of energy transfer for both direct cascades and indirect cascades, except when the wave steepness is larger than 0.28. Our model results agree well with wave measurements, obtained using field buoy data (for example, Lin and Lin, 2002). In particular, in these observations, asymmetrical wave-wave interactions were studied. They found that direct and indirect cascades both are mainly due to the 4-wave interactions when wave steep- ness is less than 0.3.展开更多
In this article, authors discuss the problem of uniform packing dimension of the image set of multiparameter stochastic processes without random uniform Holder condition, and obtain the uniform packing dimension of mu...In this article, authors discuss the problem of uniform packing dimension of the image set of multiparameter stochastic processes without random uniform Holder condition, and obtain the uniform packing dimension of multiparameter stable processes. If Z is a stable （N, d, α）-process and αN ≤ d, then the following holds with probability 1 Dim Z（E）=α Dim E for any Borel setE ∈B（R ＋^N）, where Z（E）={x：E←t∈E,Z（t）=x}, Dim （E） denotes the packing dimension of E.展开更多
Based on Kolmgorov-Johnson-Mehl-Avrami analysis, a new bainite kinetics of high strength low alloy steel in fast cooling process was developed by utilizing different experimental methods. Upper bainite transformation ...Based on Kolmgorov-Johnson-Mehl-Avrami analysis, a new bainite kinetics of high strength low alloy steel in fast cooling process was developed by utilizing different experimental methods. Upper bainite transformation morphological evolutions at a cooling rate of 8.3 K/s were directly observed by laser scanning confocal microscopy. This qualitative analysis suggests that bainite packet is more suitable to give a one-dimensional growth model if it is considered as a transformation unit. The nucleation rate of bainite packets in fast cooling process is assumed to give an a priori item. One-dimensional growth model with constant growth rate which is assumed as a function of cooling rate is adopted as well. Thus, the devel- oped new bainite kinetics is simple in expression and contains an adjustable parameter and an empirical pa rameter. Experimental results show upper bainite and lower bainite transformations in fast cooling processes. Their referential phase volume fractions are calculated by the expanded lever rule on the first derivative dilatometer curves. For the similar transformation mechanisms, upper bainite and lower bainite are considered to give the same kinetics. With considering the Nakamura＇s equation, the bainite kinetics is fitted with experimental data. Results show that bainite volume fractions and bainite transformation rates can be expressed precisely bY the newly developed bainite kinetics.展开更多
In this report the research results by Chinese scientists in 2014—2016 are summarized.The focuses are placed on the researches of the middle and upper atmosphere,specifically the researches associated with ground-bas...In this report the research results by Chinese scientists in 2014—2016 are summarized.The focuses are placed on the researches of the middle and upper atmosphere,specifically the researches associated with ground-based observation capabihty development,dynamical processes,and properties of circulation and chemistry-climate coupling of the middle atmospheric layers.展开更多
文摘Objective To investigate the feasibility and surgical effects of posterior articular process approach for the treatment of L1-L3 lumbar disc herniation.Methods A retrospective study,of17patients with upper lumbar intervertebml disc
文摘During smile evaluation and anterior esthetic construction,the anatomic and racial variations should be considered in order to achieve better matching results.The aims of this study were to validate an objective method for recording spontaneous smile process and to categorize the smile and upper lip curvature of Chinese Han-nationality youth.One hundred and eighty-eight Chinese Han-nationality youths(88 males and 100 females) ranged from 20 to 35 years of age were selected.Spontaneous smiles were elicited by watching comical movies and the dynamics of the spontaneous smile were captured continuously with a digital video camera.All subjects’ smiles were categorized into three types:commissure,cuspid and gummy smile based on video editing software and final images.Subjects’ upper lip curvatures were also measured and divided into three groups:upward,straight and downward.Reliability analysis was conducted to obtain intra-rater reliabilities on twice measurements.The Pearson Chi-square test was used to compare differences for each parameters(α=0.05).In smile classification,60.6%commissure smile,33.5%cuspid smile and 5.9%gummy smile were obtained.In upper lip measurement,26.1%upward,39.9%straight and 34.0%downward upper lip curvature were determined.The commissure smile group showed statistically significant higher percentage of straight(46.5%) and upward(40.4%) in upper lip curvatures(P<0.05),while cuspid smile group(65.1%) and gummy smile group(72.7%) showed statistically significant higher frequency in downward upper lip curvature(P<0.05).It is evident that differences in upper lip curvature and smile classification exist based on race,when comparing Chinese subjects with those of Caucasian descent,and gender.
文摘We present a three-level nested-grid ocean circulation modeling system for the Belize shelf of the western Caribbean Sea. The nested-grid system has three subcomponents： a coarse-resolution outer model of the western Caribbean Sea; an intermediate-resolution middle model of the southern Mest〉American Barrier Reef System; and a fine-resolution inner model of the Belize shelf. The two-way nesting technique based on the semi-prognostic method is used to exchange information between the three subcomponents. We discuss two applications of the nested-grid system in this study. In the first application we simulate the seasonal mean circulation in the region, with the nested system forced by monthly mean surface fluxes and boundary forcing. The model results reproduce the general circulation features on the western Caribbean Sea and mest〉scale circulation features on the Belize shelf. In the second application, we simulate the storm-induced circulation during Hurricane Mitch in 1998, with the nested-grid system forced by the combination of monthly mean forcing and idealized wind stress associated with the storm. The model results demonstrate that the storm-induced currents transport a large amount of estuarine waters from coastal regions of Honduras and Guatemala to offshore reef atolls.
基金Supported by grants from the Office of Naval Research under the ILIR program though David Taylor Model Basin, Carderock Division, NSWCCD, and NRL Coastal Ocean Physics Remote Sensing Advanced Research Initiative.
文摘Wave-wave interactions cause energy cascades. These are the most important processes in the upper ocean because they govern wave-growth and dissipation. Through indirect cascades, wave en- ergy is transferred from higher frequencies to lower frequencies, leading to wave growth. In direct cas- cades, energy is transferred from lower frequencies to the higher frequencies, which causes waves to break, and dissipation of wave energy. However, the evolution and origin of energy cascade processes are still not fully understood. In particular, for example, results from a recent theory (Kalmykov, 1998) sug- gest that the class I wave-wave interactions (defined by situations involving 4-, 6-, 8-, etc, even numbers of resonantly interacting waves) cause indirect cascades, and Class II wave-wave interactions (involving, 5-, 7-, 9-, etc, .., odd numbers of waves) cause direct cascades. In contrast to this theory, our model results indicate the 4-wave interactions can cause significant transfer of wave energy through both direct and in- direct cascades. In most situations, 4-wave interactions provide the major source of energy transfer for both direct cascades and indirect cascades, except when the wave steepness is larger than 0.28. Our model results agree well with wave measurements, obtained using field buoy data (for example, Lin and Lin, 2002). In particular, in these observations, asymmetrical wave-wave interactions were studied. They found that direct and indirect cascades both are mainly due to the 4-wave interactions when wave steep- ness is less than 0.3.
基金Supported by the National Natural Science Foundation of China.
文摘In this article, authors discuss the problem of uniform packing dimension of the image set of multiparameter stochastic processes without random uniform Holder condition, and obtain the uniform packing dimension of multiparameter stable processes. If Z is a stable （N, d, α）-process and αN ≤ d, then the following holds with probability 1 Dim Z（E）=α Dim E for any Borel setE ∈B（R ＋^N）, where Z（E）={x：E←t∈E,Z（t）=x}, Dim （E） denotes the packing dimension of E.
文摘Based on Kolmgorov-Johnson-Mehl-Avrami analysis, a new bainite kinetics of high strength low alloy steel in fast cooling process was developed by utilizing different experimental methods. Upper bainite transformation morphological evolutions at a cooling rate of 8.3 K/s were directly observed by laser scanning confocal microscopy. This qualitative analysis suggests that bainite packet is more suitable to give a one-dimensional growth model if it is considered as a transformation unit. The nucleation rate of bainite packets in fast cooling process is assumed to give an a priori item. One-dimensional growth model with constant growth rate which is assumed as a function of cooling rate is adopted as well. Thus, the devel- oped new bainite kinetics is simple in expression and contains an adjustable parameter and an empirical pa rameter. Experimental results show upper bainite and lower bainite transformations in fast cooling processes. Their referential phase volume fractions are calculated by the expanded lever rule on the first derivative dilatometer curves. For the similar transformation mechanisms, upper bainite and lower bainite are considered to give the same kinetics. With considering the Nakamura＇s equation, the bainite kinetics is fitted with experimental data. Results show that bainite volume fractions and bainite transformation rates can be expressed precisely bY the newly developed bainite kinetics.
文摘In this report the research results by Chinese scientists in 2014—2016 are summarized.The focuses are placed on the researches of the middle and upper atmosphere,specifically the researches associated with ground-based observation capabihty development,dynamical processes,and properties of circulation and chemistry-climate coupling of the middle atmospheric layers.
