Uniform molecular weight(Mw)chitosan(CS)is highly demanded in medical biomaterial industry.This present article described heterogeneous degradation of CS in aqueous HCl/ethanol solution,in which progress uniform Mw CS...Uniform molecular weight(Mw)chitosan(CS)is highly demanded in medical biomaterial industry.This present article described heterogeneous degradation of CS in aqueous HCl/ethanol solution,in which progress uniform Mw CS was successfully prepared.The Mw distribution of CS was measured by gel permeation chromatography(GPC)analysis.Moreover,the structure and properties of degraded CS were characterized by Fourier transform infrared spectroscopy(FT-IR),nuclear magnetic resonance spectroscopy(^1H NMR),X-ray diffraction(XRD)and thermogravimetric(TG)analysis.In addition,the biocompatibility of degraded CS was also assessed by hemolysis rate(HR)measurement.The Mw of CS dramatically decreased from 246 KDa to 76 k Da at the initial 30 min,and stabilized at 18 kDa after 24 h.GPC analysis results showed that the degraded CS molecular become homogenization.FT-IR and 1 H NMR analysis confirmed the basic structure of CS molecular backbone was not destroyed during this progress.Besides,the water solubility of CS was not significantly influenced by this reaction.Moreover,the XRD analysis revealed that crystallinity of degraded CS increased from 70.32% to 99.25%with time.The TG analysis showed improved thermal stability of degraded CS.HR measurement demonstrated the degraded CS possessed excellent biocompatibility.This simple and efficient heterogeneous degradation would open up a new route to produce uniform Mw CS.展开更多
Panel data combine cross-section data and time series data. If the cross-section is locations, there is a need to check the correlation among locations. ρ and λ are parameters in generalized spatial model to cover e...Panel data combine cross-section data and time series data. If the cross-section is locations, there is a need to check the correlation among locations. ρ and λ are parameters in generalized spatial model to cover effect of correlation between locations. Value of ρ or λ will influence the goodness of fit model, so it is important to make parameter estimation. The effect of another location is covered by making contiguity matrix until it gets spatial weighted matrix (W). There are some types of W—uniform W, binary W, kernel Gaussian W and some W from real case of economics condition or transportation condition from locations. This study is aimed to compare uniform W and kernel Gaussian W in spatial panel data model using RMSE value. The result of analysis showed that uniform weight had RMSE value less than kernel Gaussian model. Uniform W had stabil value for all the combinations.展开更多
In a dynamic CT, the acquired projections are corrupted due to strong dynamic nature of the object, for example: lungs, heart etc. In this paper, we present fan-beam reconstruction algorithm without position-dependent...In a dynamic CT, the acquired projections are corrupted due to strong dynamic nature of the object, for example: lungs, heart etc. In this paper, we present fan-beam reconstruction algorithm without position-dependent backprojection weight which compensates for the time-dependent translational, uniform scaling and rotational deformations occurring in the object of interest during the data acquisition process. We shall also compare the computational cost of the proposed reconstruction algorithm with the existing one which has position-dependent weight. To accomplish the objective listed above, we first formulate admissibility conditions on deformations that is required to exactly reconstruct the object from acquired sequential deformed projections and then derive the reconstruction algorithm to compensate the above listed deformations satisfying the admissibility conditions. For this, 2-D time-dependent deformation model is incorporated in the fan-beam FBP reconstruction algorithm with no backprojection weight, assuming the motion parameters being known. Finally the proposed reconstruction algorithm is evaluated with the motion corrupted projection data simulated on the computer.展开更多
目的化工园区救援机器人的路径规划是目前研究的热点,针对救援机器人在路径规划中使用传统A^(*)算法存在遍历冗余节点、内存消耗较大和运算速度较慢的问题,提出一种改进的A^(*)算法。方法设计了自适应权重评价函数,用于动态调整实际代价...目的化工园区救援机器人的路径规划是目前研究的热点,针对救援机器人在路径规划中使用传统A^(*)算法存在遍历冗余节点、内存消耗较大和运算速度较慢的问题,提出一种改进的A^(*)算法。方法设计了自适应权重评价函数,用于动态调整实际代价,以提升算法的效率与收敛速度;采用跳点搜索策略(Jump Point Search,JPS)来筛选跳点,降低内存消耗和节点估计;运用三次均匀B样条曲线对优化后的路径进行处理,提高救援机器人前进的稳定性和可行性。结果通过构建化工园区Unity3D仿真场景,对救援机器人路径规划问题进行仿真研究,仿真结果表明:改进后的A^(*)算法展现出较高的效率及准确性。结论该算法为化工园区救援机器人的路径规划提供了一种更高效、更智能的解决方案,满足化工园区路径快速规划的需求。展开更多
Let x （xn）≥1 be a martingale on a noncommutative probability space n （M, r） and （wn）n≥1 a sequence of positive numbers such that Wn = ∑ k=1^n wk →∞ as n →∞ We prove that x = （x.）n≥1 converges in E（M...Let x （xn）≥1 be a martingale on a noncommutative probability space n （M, r） and （wn）n≥1 a sequence of positive numbers such that Wn = ∑ k=1^n wk →∞ as n →∞ We prove that x = （x.）n≥1 converges in E（M） if and only if （σn（x）n≥1 converges in E（.hd）, where E（A//） is a noncommutative rearrangement invariant Banach function space with the Fatou property and σn（x） is given by σn（x） = 1/Wn ∑k=1^n wkxk, n=1, 2, .If in addition, E（Ad） has absolutely continuous norm, then, （an（x））≥1 converges in E（.M） if and only if x = （Xn）n≥1 is uniformly integrable and its limit in measure topology x∞∈ E（M）.展开更多
In this paper,we study a semi-linear reaction-diffusion system with a weighted nonlocal source,subject to the null Dirichlet boundary condition.Under certain conditions,we prove that the classical solution exists glob...In this paper,we study a semi-linear reaction-diffusion system with a weighted nonlocal source,subject to the null Dirichlet boundary condition.Under certain conditions,we prove that the classical solution exists globally and blows up in finite time respectively,and then obtain the uniform blow-up rate in the interior.展开更多
In this note, we experimentally demonstrate, on a variety of analytic and nonanalytic functions, the novel observation that if the least squares polynomial approximation is repeated as weight in a second, now weighted...In this note, we experimentally demonstrate, on a variety of analytic and nonanalytic functions, the novel observation that if the least squares polynomial approximation is repeated as weight in a second, now weighted, least squares approximation, then this new, second, approximation is nearly perfect in the uniform sense, barely needing any further, say, Remez correction.展开更多
基金supported by the National Natural Science Foundation of China(Nos.U1706212 and 81671828)
文摘Uniform molecular weight(Mw)chitosan(CS)is highly demanded in medical biomaterial industry.This present article described heterogeneous degradation of CS in aqueous HCl/ethanol solution,in which progress uniform Mw CS was successfully prepared.The Mw distribution of CS was measured by gel permeation chromatography(GPC)analysis.Moreover,the structure and properties of degraded CS were characterized by Fourier transform infrared spectroscopy(FT-IR),nuclear magnetic resonance spectroscopy(^1H NMR),X-ray diffraction(XRD)and thermogravimetric(TG)analysis.In addition,the biocompatibility of degraded CS was also assessed by hemolysis rate(HR)measurement.The Mw of CS dramatically decreased from 246 KDa to 76 k Da at the initial 30 min,and stabilized at 18 kDa after 24 h.GPC analysis results showed that the degraded CS molecular become homogenization.FT-IR and 1 H NMR analysis confirmed the basic structure of CS molecular backbone was not destroyed during this progress.Besides,the water solubility of CS was not significantly influenced by this reaction.Moreover,the XRD analysis revealed that crystallinity of degraded CS increased from 70.32% to 99.25%with time.The TG analysis showed improved thermal stability of degraded CS.HR measurement demonstrated the degraded CS possessed excellent biocompatibility.This simple and efficient heterogeneous degradation would open up a new route to produce uniform Mw CS.
文摘Panel data combine cross-section data and time series data. If the cross-section is locations, there is a need to check the correlation among locations. ρ and λ are parameters in generalized spatial model to cover effect of correlation between locations. Value of ρ or λ will influence the goodness of fit model, so it is important to make parameter estimation. The effect of another location is covered by making contiguity matrix until it gets spatial weighted matrix (W). There are some types of W—uniform W, binary W, kernel Gaussian W and some W from real case of economics condition or transportation condition from locations. This study is aimed to compare uniform W and kernel Gaussian W in spatial panel data model using RMSE value. The result of analysis showed that uniform weight had RMSE value less than kernel Gaussian model. Uniform W had stabil value for all the combinations.
文摘In a dynamic CT, the acquired projections are corrupted due to strong dynamic nature of the object, for example: lungs, heart etc. In this paper, we present fan-beam reconstruction algorithm without position-dependent backprojection weight which compensates for the time-dependent translational, uniform scaling and rotational deformations occurring in the object of interest during the data acquisition process. We shall also compare the computational cost of the proposed reconstruction algorithm with the existing one which has position-dependent weight. To accomplish the objective listed above, we first formulate admissibility conditions on deformations that is required to exactly reconstruct the object from acquired sequential deformed projections and then derive the reconstruction algorithm to compensate the above listed deformations satisfying the admissibility conditions. For this, 2-D time-dependent deformation model is incorporated in the fan-beam FBP reconstruction algorithm with no backprojection weight, assuming the motion parameters being known. Finally the proposed reconstruction algorithm is evaluated with the motion corrupted projection data simulated on the computer.
文摘目的化工园区救援机器人的路径规划是目前研究的热点,针对救援机器人在路径规划中使用传统A^(*)算法存在遍历冗余节点、内存消耗较大和运算速度较慢的问题,提出一种改进的A^(*)算法。方法设计了自适应权重评价函数,用于动态调整实际代价,以提升算法的效率与收敛速度;采用跳点搜索策略(Jump Point Search,JPS)来筛选跳点,降低内存消耗和节点估计;运用三次均匀B样条曲线对优化后的路径进行处理,提高救援机器人前进的稳定性和可行性。结果通过构建化工园区Unity3D仿真场景,对救援机器人路径规划问题进行仿真研究,仿真结果表明:改进后的A^(*)算法展现出较高的效率及准确性。结论该算法为化工园区救援机器人的路径规划提供了一种更高效、更智能的解决方案,满足化工园区路径快速规划的需求。
基金supported by the National Natural Science Foundation of China (11071190)
文摘Let x （xn）≥1 be a martingale on a noncommutative probability space n （M, r） and （wn）n≥1 a sequence of positive numbers such that Wn = ∑ k=1^n wk →∞ as n →∞ We prove that x = （x.）n≥1 converges in E（M） if and only if （σn（x）n≥1 converges in E（.hd）, where E（A//） is a noncommutative rearrangement invariant Banach function space with the Fatou property and σn（x） is given by σn（x） = 1/Wn ∑k=1^n wkxk, n=1, 2, .If in addition, E（Ad） has absolutely continuous norm, then, （an（x））≥1 converges in E（.M） if and only if x = （Xn）n≥1 is uniformly integrable and its limit in measure topology x∞∈ E（M）.
基金Project supported by the Research Program of Natural Science of Universities in Jiangsu Province (Grant No.09KJD110008)the Natural Science Foundation of Nanjing Xiaozhuang University (Grant No.005NXY11)
文摘In this paper,we study a semi-linear reaction-diffusion system with a weighted nonlocal source,subject to the null Dirichlet boundary condition.Under certain conditions,we prove that the classical solution exists globally and blows up in finite time respectively,and then obtain the uniform blow-up rate in the interior.
文摘In this note, we experimentally demonstrate, on a variety of analytic and nonanalytic functions, the novel observation that if the least squares polynomial approximation is repeated as weight in a second, now weighted, least squares approximation, then this new, second, approximation is nearly perfect in the uniform sense, barely needing any further, say, Remez correction.
