The liquid state undercoolability and crystal growth kinetics of ternary Ni-5%Cu-5%Sn and Ni-10%Cu-10%Sn alloys are investigated by the glass fluxing method. In these two alloys, experimental maximum undercoolings of ...The liquid state undercoolability and crystal growth kinetics of ternary Ni-5%Cu-5%Sn and Ni-10%Cu-10%Sn alloys are investigated by the glass fluxing method. In these two alloys, experimental maximum undercoolings of 304 K (0.18TL ) and 286K (0.17TL ) are achieved and the dendritic growth velocities attain 39.8 and 25.1 m/s, respectively. The transition of morphology from coarse dendrite into equiaxed structure occurs and the grain size of the a (Ni) phase decreases remarkably when the undercooling increases. Both the lattice constant and microhardness increase obviously with the enhancement of undercooling. The enrichment of Cu and Sn solute contents reduces the dendritic growth velocity, while enhances the lattice constant and microhardness of a (Ni) phase.展开更多
The grain growth behavior in reactive spray formed 7075+2.91 vol percent TiCAl alloy was studied and compared with that of spray formed 7075 Al alloy at semi-solid state. Theeffects of in-situ TiC particles on the mic...The grain growth behavior in reactive spray formed 7075+2.91 vol percent TiCAl alloy was studied and compared with that of spray formed 7075 Al alloy at semi-solid state. Theeffects of in-situ TiC particles on the microstructure of spray formed 7075 Al alloy were alsoinvestigated. The specimens were heat-treated isothermally at various temperatures between thesolidus and liquidus of 7075 Al alloy for times in the range of 10-60 min, then quenched in water.The microstructure of reheated specimens was characterized using scanning electron microscopy andoptical microscopy. The grain size was measured using a mean linear intercept method. Results showthat the in-situ TiC particles can effectively retard grain growth and refine the grain at a limitedsize. The grain growth exponent in Arrhenius equation increases from 2 to 3, which indicates thatthe in-situ TiC particles have the significant pinning effect on grain coarsening in the semi-solidstate.展开更多
By analyzing the importance of influencing factors and conducting a comparative study of the effects of different sorting algorithms, a new method is proposed that is suitable for classifying the growth state of a nat...By analyzing the importance of influencing factors and conducting a comparative study of the effects of different sorting algorithms, a new method is proposed that is suitable for classifying the growth state of a natural Metasequoia glyptostroboides Hu and W.C. Cheng population. We studied 2817 M. glyptostroboides trees over 100 years old and analyzed their growth state by measuring 15 factors from stumpage, site condition, and environmental data. The dimensionality of all factors were reduced using the random forest algorithm, and we classified the remaining factors using the following algorithms: random forest, back-propagation(BP) neural networks, and support vector machine(SVM). The applicability of each sorting algorithm was analyzed. When all the d factors are used for classification and modeling, the model's overall accuracy,kappa coefficient and test accuracy were 85.5%, 0.739 and 85.8%, respectively. By reducing the dimensionality of the factors using the random forest algorithm, 11 factors most strongly influenced the classifications of the growth state of the Metasequoia population: diameter at breast height,height, crown width, age from stumpage data; longitude,latitude, elevation, slope aspect, gradient and slope position from the site condition data; and the edge of the field from the environmental data. For classifying the Metasequoia population, the random forest algorithm has the highest overall accuracy at 87.2%, which is 3.4 and 2.3% higher than the BP neural networks and SVM algorithms,respectively. The SVM algorithm is superior to the random forest algorithm with respect to classifying the state of mortality. The combination of the random forest and SVM algorithms and their combined information can be used to classify and predict the growth state of this natural M.glyptostroboides population to provide a scientific basis for its effective protection.展开更多
The main goal of the present paper is to present a mathematical framework for modelling tumour growth based on stress state decomposition technique (SSDT). This is a straightforward extension of the model for multi-ph...The main goal of the present paper is to present a mathematical framework for modelling tumour growth based on stress state decomposition technique (SSDT). This is a straightforward extension of the model for multi-phase nonsaturated soil consolidation with pollutant transport presented by the authors and may be regarded as an alternative to classical frameworks based on TCAT theory. In this preliminary work, the Representative Volume Element (RVE) for tumour is proposed along with its comparison with the corresponding one for soils modelling developed formerly by the authors. Equations standing for tumour phase are flawlessly brought into correspondence with those of gaseous phase in the soil problem showing that a similar task may be carried out for the remainders phases taking part in both RVEs. Furthermore, stresses induced by nonlinear saturation and permeability dependence on suction for soil interstitial fluids transport finds its counterpart on the contact between the cancer cell membrane and interstitial fluids rendering a higher primary variables coupling degree than what was attained in TCAT theory. From these preliminaries assessments, it may be put forward that likewise the stress state decomposition procedure stands for an alternative for modelling multi-phase nonsaturated soil consolidation with pollutant transport;it does for modelling cancer as well.展开更多
Negative trends in the monthly MODerate resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) time-series were found to be widespread in natural (non-cropland) ecosystems of the eastern United S...Negative trends in the monthly MODerate resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) time-series were found to be widespread in natural (non-cropland) ecosystems of the eastern United Statesfrom 2000 to 2010. Four sub-regions were detected with significant declines in summed growing season (May-September) EVI, namely theUpper Great Lakes, the Southern Appalachian, the Mid-Atlantic, and the southeastern Coastal Plain forests ecosystems. More than 20% of the undeveloped ecosystem areas in the four sub-regions with significant negative EVI growing season trends were classified as forested land cover over the entire study period. We detected relationships between annual temperature and precipitation patterns and negative forest EVI trends across these regions. Change patterns in both the climate moisture index (CMI) and growing degree days (GDD) were associated with declining forest EVI growing season trends. We conclude that temperature warming-induced change and variability of precipitation at local and regional scales may have altered the growth trends of large forested areas of the easternUnited Statesover the past decade.展开更多
BACKGROUND: Vascular endothelial growth factor (VEGF) is able to regulate blood spinal cord barrier function as well as influence neovascularization and cause edema. OBJECTIVE: Through establishment of a rabbit mo...BACKGROUND: Vascular endothelial growth factor (VEGF) is able to regulate blood spinal cord barrier function as well as influence neovascularization and cause edema. OBJECTIVE: Through establishment of a rabbit model of syringomyelia, to explore the correlation between VEGF protein and mRNA expressions and function of blood spinal cord barrier and edema degree of spinal cord in presyrinx state. DESIGN, TIME AND SETTING: Randomized controlled animal study was performed in the Tumor Institute of the Fourth Hospital, Hebei Medical University from January to June 2007. MATERIALS: Atotal of 0.6 mL Kaolin solution (250 g/L, 37℃) was injected into the cisterna magna of 40 rabbits in the kaolin group to establish syringomyelia models. Goat anti-rabbit VEGF monoclonal antibody was provided by DIACLONE Company, USA; RT-PCR related reagents were provided by Huamei Bioengineering Co., Ltd., Beijing. METHODS: Sixty Chinese white rabbits were divided randomly into two groups: Kaolin group (n = 40) and control group (n = 20). Physiological saline (0.6 mL at 37℃) was injected in rabbits of control group. On days 1,3, 7, 14 and 21 after kaolin injection, cervical cords samples were harvested after sacrifice of animal. MAIN OUTCOME MEASURES: VEGF protein and mRNA expressions were detected by immunohistochemistry and RT-PCR on days 1, 3, 7, 14, and 21 after kaolin injection. A quantitative analysis of blood spinal cord barrier function was performed by Evans blue technique. Water content of the spinal cord was measured by dry-wet weight technique. The correlation between the expression of VEGF protein and mRNA and the function of blood spinal cord barrier in the upper cervical cord of the presyrinx state was analyzed by linear correlation analysis. RESULTS: The water content and Evans blue content increased in the kaolin group on days 1 and 3 postoperatively compared with the control group (F = 7.387, 61.35, P 〈 0.05, 0.01), and reached a peak on day 7 (F = 135.94, 528.35, P 〈 0.01). They declined slowly to day 21 postoperatively, but both contents were still higher than the control group (F = 11.51, 58.63, P 〈 0.01). VEGF protein expression increased on day 1, and stronger positive expression was seen on days 3, 7 and 14. It decreased on day 21. VEGF protein expression was higher than the control group at each time point (F = 137.4-468.5, P 〈 0.01 ). VEGF mRNA expression showed the same pattern in the cervical cord at different time points. By statistical analysis, the expression of VEGF protein and mRNA had a significantly positive correlation with the structural and functional changes of the blood spinal cord barrier in the presyrinx state (r = 0.604-0.979, P 〈 0.05). CONCLUSION: In the presyrinx state of syringomyelia, the expressions of VEGF protein and mRNA can influence the structure and function of the blood spinal cord barrier and play an important role in the formation and development of spinal cord edema and syringomyelia.展开更多
In this paper, we study the following Schrödinger-Kirchhoff equation where V(x) ≥ 0 and vanishes on an open set of R<sup>2</sup> and f has critical exponential growth. By using a version of Trudinger...In this paper, we study the following Schrödinger-Kirchhoff equation where V(x) ≥ 0 and vanishes on an open set of R<sup>2</sup> and f has critical exponential growth. By using a version of Trudinger-Moser inequality and variational methods, we obtain the existence of ground state solutions for this problem.展开更多
This paper develops a generalized dynamical model to describe the interactive dynamics between normal cells, tumor cells, immune cells, drug therapy, electromagnetic field of the human cells, extracellular heat and fl...This paper develops a generalized dynamical model to describe the interactive dynamics between normal cells, tumor cells, immune cells, drug therapy, electromagnetic field of the human cells, extracellular heat and fluid transfer, and intercellular fractional mass of Oxygen, cell acidity and Pancreatin enzyme. The overall dynamics stability, controllability and observability have been investigated. Moreover, Cesium therapy is considered as a control input to the 11-dimensional dynamics using state-feedback controlled system and pole placement technique. This approach is found to be effective in driving the desired rate of tumor cell kill and converging the system to healthy equilibrium state. Furthermore, the ranges of the system dynamics parameters which lead to instability and growth of tumor cells have been identified. Finally, simulation results are demonstrated to verify the effectiveness of the applied approach which can be implemented successfully to cancer patients.展开更多
针对以指挥信息系统为典型的复杂任务型软件试验鉴定领域中可靠性评估问题,在总结现有评价方法的基础上,提出了基于系统状态特征分析的可靠性评估方法。首先,从软件使命任务的角度解析系统的状态特征,设计充分覆盖系统典型应用样式及状...针对以指挥信息系统为典型的复杂任务型软件试验鉴定领域中可靠性评估问题,在总结现有评价方法的基础上,提出了基于系统状态特征分析的可靠性评估方法。首先,从软件使命任务的角度解析系统的状态特征,设计充分覆盖系统典型应用样式及状态特征的测试用例,通过定义“使用强度”,替代原有可靠性评价中“持续时间”指标,在此基础上收集可靠性失效数据,并给出软件可靠性增长模型(software reliability and growth model,SRGM)参数估计及可靠性评估过程。最后通过某任务型软件的可靠性评估试验,验证提出方法在工程实践中的可行性,同时给出了工程示例中收集的真实失效数据和SRGM参数估计结果,确保研究成果真实性和可复现性。展开更多
目的:分析母亲声音干预对NICU早产儿生长发育及睡眠的影响。方法:选取2023年1月至2023年11月福建省晋江市医院NICU收治的早产儿98例作为研究对象,按照随机数字表法随机分为观察组和对照组,每组49例。对照组接受音乐疗法,观察组接受母亲...目的:分析母亲声音干预对NICU早产儿生长发育及睡眠的影响。方法:选取2023年1月至2023年11月福建省晋江市医院NICU收治的早产儿98例作为研究对象,按照随机数字表法随机分为观察组和对照组,每组49例。对照组接受音乐疗法,观察组接受母亲声音干预。比较2组体格发育指标、行为状态与安静睡眠周期(QSC),行为状态评估采用安德森行为状态量表(ABSS)。结果:观察组体质量增长速率快于对照组(P<0.05)。观察组在干预中10 min、干预后5 min ABSS评分低于对照组(P<0.05)。观察组QSC平均时间、总时间长于对照组,中断次数较少(P<0.05)。结论:母亲声音干预可改善NICU早产儿行为状态与睡眠状态,促进体格发育。展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 51327901 and 51301138the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No 20126102120064+1 种基金the Aviation Science Foundation of China under Grant No 2014ZF53069the Fundamental Research Funds for the Central Universities under Grant No3102014KYJD044
文摘The liquid state undercoolability and crystal growth kinetics of ternary Ni-5%Cu-5%Sn and Ni-10%Cu-10%Sn alloys are investigated by the glass fluxing method. In these two alloys, experimental maximum undercoolings of 304 K (0.18TL ) and 286K (0.17TL ) are achieved and the dendritic growth velocities attain 39.8 and 25.1 m/s, respectively. The transition of morphology from coarse dendrite into equiaxed structure occurs and the grain size of the a (Ni) phase decreases remarkably when the undercooling increases. Both the lattice constant and microhardness increase obviously with the enhancement of undercooling. The enrichment of Cu and Sn solute contents reduces the dendritic growth velocity, while enhances the lattice constant and microhardness of a (Ni) phase.
基金This work was financially supported by the National Natural Science Foundation of China (No.50171010)
文摘The grain growth behavior in reactive spray formed 7075+2.91 vol percent TiCAl alloy was studied and compared with that of spray formed 7075 Al alloy at semi-solid state. Theeffects of in-situ TiC particles on the microstructure of spray formed 7075 Al alloy were alsoinvestigated. The specimens were heat-treated isothermally at various temperatures between thesolidus and liquidus of 7075 Al alloy for times in the range of 10-60 min, then quenched in water.The microstructure of reheated specimens was characterized using scanning electron microscopy andoptical microscopy. The grain size was measured using a mean linear intercept method. Results showthat the in-situ TiC particles can effectively retard grain growth and refine the grain at a limitedsize. The grain growth exponent in Arrhenius equation increases from 2 to 3, which indicates thatthe in-situ TiC particles have the significant pinning effect on grain coarsening in the semi-solidstate.
基金supported by Study on Spatial Environmental Effect Model and Forestation Decision Support System for Forest Vegetation in Beijing(6161001)
文摘By analyzing the importance of influencing factors and conducting a comparative study of the effects of different sorting algorithms, a new method is proposed that is suitable for classifying the growth state of a natural Metasequoia glyptostroboides Hu and W.C. Cheng population. We studied 2817 M. glyptostroboides trees over 100 years old and analyzed their growth state by measuring 15 factors from stumpage, site condition, and environmental data. The dimensionality of all factors were reduced using the random forest algorithm, and we classified the remaining factors using the following algorithms: random forest, back-propagation(BP) neural networks, and support vector machine(SVM). The applicability of each sorting algorithm was analyzed. When all the d factors are used for classification and modeling, the model's overall accuracy,kappa coefficient and test accuracy were 85.5%, 0.739 and 85.8%, respectively. By reducing the dimensionality of the factors using the random forest algorithm, 11 factors most strongly influenced the classifications of the growth state of the Metasequoia population: diameter at breast height,height, crown width, age from stumpage data; longitude,latitude, elevation, slope aspect, gradient and slope position from the site condition data; and the edge of the field from the environmental data. For classifying the Metasequoia population, the random forest algorithm has the highest overall accuracy at 87.2%, which is 3.4 and 2.3% higher than the BP neural networks and SVM algorithms,respectively. The SVM algorithm is superior to the random forest algorithm with respect to classifying the state of mortality. The combination of the random forest and SVM algorithms and their combined information can be used to classify and predict the growth state of this natural M.glyptostroboides population to provide a scientific basis for its effective protection.
文摘The main goal of the present paper is to present a mathematical framework for modelling tumour growth based on stress state decomposition technique (SSDT). This is a straightforward extension of the model for multi-phase nonsaturated soil consolidation with pollutant transport presented by the authors and may be regarded as an alternative to classical frameworks based on TCAT theory. In this preliminary work, the Representative Volume Element (RVE) for tumour is proposed along with its comparison with the corresponding one for soils modelling developed formerly by the authors. Equations standing for tumour phase are flawlessly brought into correspondence with those of gaseous phase in the soil problem showing that a similar task may be carried out for the remainders phases taking part in both RVEs. Furthermore, stresses induced by nonlinear saturation and permeability dependence on suction for soil interstitial fluids transport finds its counterpart on the contact between the cancer cell membrane and interstitial fluids rendering a higher primary variables coupling degree than what was attained in TCAT theory. From these preliminaries assessments, it may be put forward that likewise the stress state decomposition procedure stands for an alternative for modelling multi-phase nonsaturated soil consolidation with pollutant transport;it does for modelling cancer as well.
文摘Negative trends in the monthly MODerate resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) time-series were found to be widespread in natural (non-cropland) ecosystems of the eastern United Statesfrom 2000 to 2010. Four sub-regions were detected with significant declines in summed growing season (May-September) EVI, namely theUpper Great Lakes, the Southern Appalachian, the Mid-Atlantic, and the southeastern Coastal Plain forests ecosystems. More than 20% of the undeveloped ecosystem areas in the four sub-regions with significant negative EVI growing season trends were classified as forested land cover over the entire study period. We detected relationships between annual temperature and precipitation patterns and negative forest EVI trends across these regions. Change patterns in both the climate moisture index (CMI) and growing degree days (GDD) were associated with declining forest EVI growing season trends. We conclude that temperature warming-induced change and variability of precipitation at local and regional scales may have altered the growth trends of large forested areas of the easternUnited Statesover the past decade.
文摘BACKGROUND: Vascular endothelial growth factor (VEGF) is able to regulate blood spinal cord barrier function as well as influence neovascularization and cause edema. OBJECTIVE: Through establishment of a rabbit model of syringomyelia, to explore the correlation between VEGF protein and mRNA expressions and function of blood spinal cord barrier and edema degree of spinal cord in presyrinx state. DESIGN, TIME AND SETTING: Randomized controlled animal study was performed in the Tumor Institute of the Fourth Hospital, Hebei Medical University from January to June 2007. MATERIALS: Atotal of 0.6 mL Kaolin solution (250 g/L, 37℃) was injected into the cisterna magna of 40 rabbits in the kaolin group to establish syringomyelia models. Goat anti-rabbit VEGF monoclonal antibody was provided by DIACLONE Company, USA; RT-PCR related reagents were provided by Huamei Bioengineering Co., Ltd., Beijing. METHODS: Sixty Chinese white rabbits were divided randomly into two groups: Kaolin group (n = 40) and control group (n = 20). Physiological saline (0.6 mL at 37℃) was injected in rabbits of control group. On days 1,3, 7, 14 and 21 after kaolin injection, cervical cords samples were harvested after sacrifice of animal. MAIN OUTCOME MEASURES: VEGF protein and mRNA expressions were detected by immunohistochemistry and RT-PCR on days 1, 3, 7, 14, and 21 after kaolin injection. A quantitative analysis of blood spinal cord barrier function was performed by Evans blue technique. Water content of the spinal cord was measured by dry-wet weight technique. The correlation between the expression of VEGF protein and mRNA and the function of blood spinal cord barrier in the upper cervical cord of the presyrinx state was analyzed by linear correlation analysis. RESULTS: The water content and Evans blue content increased in the kaolin group on days 1 and 3 postoperatively compared with the control group (F = 7.387, 61.35, P 〈 0.05, 0.01), and reached a peak on day 7 (F = 135.94, 528.35, P 〈 0.01). They declined slowly to day 21 postoperatively, but both contents were still higher than the control group (F = 11.51, 58.63, P 〈 0.01). VEGF protein expression increased on day 1, and stronger positive expression was seen on days 3, 7 and 14. It decreased on day 21. VEGF protein expression was higher than the control group at each time point (F = 137.4-468.5, P 〈 0.01 ). VEGF mRNA expression showed the same pattern in the cervical cord at different time points. By statistical analysis, the expression of VEGF protein and mRNA had a significantly positive correlation with the structural and functional changes of the blood spinal cord barrier in the presyrinx state (r = 0.604-0.979, P 〈 0.05). CONCLUSION: In the presyrinx state of syringomyelia, the expressions of VEGF protein and mRNA can influence the structure and function of the blood spinal cord barrier and play an important role in the formation and development of spinal cord edema and syringomyelia.
文摘In this paper, we study the following Schrödinger-Kirchhoff equation where V(x) ≥ 0 and vanishes on an open set of R<sup>2</sup> and f has critical exponential growth. By using a version of Trudinger-Moser inequality and variational methods, we obtain the existence of ground state solutions for this problem.
文摘This paper develops a generalized dynamical model to describe the interactive dynamics between normal cells, tumor cells, immune cells, drug therapy, electromagnetic field of the human cells, extracellular heat and fluid transfer, and intercellular fractional mass of Oxygen, cell acidity and Pancreatin enzyme. The overall dynamics stability, controllability and observability have been investigated. Moreover, Cesium therapy is considered as a control input to the 11-dimensional dynamics using state-feedback controlled system and pole placement technique. This approach is found to be effective in driving the desired rate of tumor cell kill and converging the system to healthy equilibrium state. Furthermore, the ranges of the system dynamics parameters which lead to instability and growth of tumor cells have been identified. Finally, simulation results are demonstrated to verify the effectiveness of the applied approach which can be implemented successfully to cancer patients.
文摘针对以指挥信息系统为典型的复杂任务型软件试验鉴定领域中可靠性评估问题,在总结现有评价方法的基础上,提出了基于系统状态特征分析的可靠性评估方法。首先,从软件使命任务的角度解析系统的状态特征,设计充分覆盖系统典型应用样式及状态特征的测试用例,通过定义“使用强度”,替代原有可靠性评价中“持续时间”指标,在此基础上收集可靠性失效数据,并给出软件可靠性增长模型(software reliability and growth model,SRGM)参数估计及可靠性评估过程。最后通过某任务型软件的可靠性评估试验,验证提出方法在工程实践中的可行性,同时给出了工程示例中收集的真实失效数据和SRGM参数估计结果,确保研究成果真实性和可复现性。
文摘目的:分析母亲声音干预对NICU早产儿生长发育及睡眠的影响。方法:选取2023年1月至2023年11月福建省晋江市医院NICU收治的早产儿98例作为研究对象,按照随机数字表法随机分为观察组和对照组,每组49例。对照组接受音乐疗法,观察组接受母亲声音干预。比较2组体格发育指标、行为状态与安静睡眠周期(QSC),行为状态评估采用安德森行为状态量表(ABSS)。结果:观察组体质量增长速率快于对照组(P<0.05)。观察组在干预中10 min、干预后5 min ABSS评分低于对照组(P<0.05)。观察组QSC平均时间、总时间长于对照组,中断次数较少(P<0.05)。结论:母亲声音干预可改善NICU早产儿行为状态与睡眠状态,促进体格发育。