FEATURE SOLID MODELING TOOL SYSTEM:FSMTS

In conformity with the principle of Design for Manufacture,feature-based design strate-(?)es have been developed.As the“feature”is relevant to the“macro process plan”and“macro NCprograms”,obviously,“feature”is beyond the power of conventional solid modellers.Neverthe-less,substantial breakthrough has not been made in the solid modeling field,except“feature at-taching”or“feature recognizing”methods have been taken on.In this paper,the theory,concepts,system architecture,and algorithm principles of solid modeling tool system have beenrepresented.The practice of Feature Solid Modeling Tool System (FSMTS) developed atHuazhong University has proved that the tool may be a new foundation of Feature-Based Design.     

Weighted progressive interpolation of Loop subdivision surfaces

This paper proposes a weighted progressive method for constructing a Loop subdivision surface interpolating a given mesh. The convergent rate of the weighted progressive interpolation can be controlled by adjusting the weight of the iteration. For different weights in the available range, the limit meshes are the same as that of the reverse solution by directly solving a linear system. The theoretical value for the optimal weight is given based on the smallest eigenvalue of the collocation matrix. An appropriate value of the weight is assigned based on both theoretical analysis and numerical experiments.     

在红利支付情形下考虑负效用的消费投资问题

研究了经济代理人面临红利支付和劳动负效用情形下投资与退休选择问题,其中考虑了风险资产派发红利及劳动会给经济代理人带来效用损失的情形.代理人享有退休选择权,退休决策使得代理人避免了劳动负效用,却必须要放弃工资收入.代理人效用来自消费,并且受劳动负效用的直接影响.利用动态规划的方法去解自由边值问题,得到了代理人临界财富水平和最优消费投资组合策略显示解.     

Automated High-Throughput Fatty Acid Analysis of Umbilical Cord Serum and Application to an Epidemiological Study

Large population studies show that polyunsaturated fatty acids are important for human health, but determining relationships between the health benefits and the fatty acid content has been hampered by the unavailability of labor-effective high-throughput technologies. An automated high throughput fatty acid analysis was developed from a previous procedure based on direct transesterification including the automation of chemical procedures, data acquisition and automatic data processing. The method was validated and applied to umbilical cord serum samples in an epidemiological study. The method was linear in the range of 1–600 μg/mL serum with r ² ≥0.99. The within-run CV was <5.4% for 23 fatty acids and a range of recoveries over three concentrations were 76–119% in a low-lipid matrix with the exception of 14:0. The fatty acid concentration as measured by the robotic method for human plasma was in good agreement with the Lepage & Roy method. The fatty acid profile in umbilical cord serum from American subjects (n = 287) showed an average of 38.0, 24.9, 32.0 and 4.6% of total fatty acids for saturates, monounsaturates, n-6 and n-3 polyunsaturates, respectively. This is the first report of a complete, validated, cost-effective, automated, high throughput fatty acid measurement method along with application to a population-based study. Automated fatty acid analysis coupled with automated data processing greatly facilitates the high throughput, 72 samples transesterified in 6 h, required for large population-based studies.     

正压开放式气力输送水泥粉体临界料位影响因素实验研究*

本文采用相似理论模拟建立了目前工业常用的正压开放式气力输送系统。该系统可以有效监控固体质量流率、固体料位、气力输送及气体流量等参数。在此系统上,以水泥粉体为输送物料,压缩空气为输送动力进行开放式气力输送研究。通过改变输送母管内的输送压力、气体流量、固体质量流率等操作参数得出临界料位的变化规律,进而得出影响临界料位的主要因素,为本类开放式气力输送的临界料位的确定与监控提供指导。     

Improving the Surface Performance of Electrospun Air Filter Paper Using Multi-walled Carbon Nanotubes

In this study, air filter base paper (P) was used as the receiving substrate, polyvinyl alcohol (PVA) and PVA/multi-walled carbon nanotube (MWCNT) spinning solutions were used to prepare electrospun air filter papers (P-PVA and P-PVA/MWCNT, respectively). Then, P-PVA/MWCNT was calendered under different pressures. The effect of MWCNTs on the surface performance of P-PVA/MWCNT was explored and the influence of calendering technology on their structure and filtration characteristics was analyzed. Electron scanning microscope observation showed that the PVA nanofibers on the surface of P-PVA/MWCNT had no beading, and MWCNTs weakened the surface electrostatic phenomenon and had a good micromorphology. During the calendering process, with an increase in pressure, the mean pore size and surface roughness of P-PVA/MWCNT decreased, the initial resistance increased, and the filtration efficiency changed slightly.     

Preparation of High-precision Electrospun Nanoair Filter Paper for Air Purification

Electrospinning technology has become a research hotspot because of its advantages, such as simple operation, low cost, large specific surface area, high porosity, and good fiber continuity. Here, a new type of composite nanoair filter paper was prepared using electrospinning technology. To improve the practicability of air filter base paper, phenolic resin was used as a curing agent to improve the strength. The results show that the electrospun nanoair filter paper with air filter paper as the receiving substrate and polyvinyl alcohol (PVA) solution as the spinning solution excellently performed in all aspects. The influence of the thickness (spinning time) of the PVA nanofiber membrane on the micromorphology, physical properties, and filtration performance of the electrospun nanoair filter paper was analyzed. According to the ISO 5011-2014 standard, the initial resistance, filtration efficiency, mean pore size, and dust capacity of the electrospun nanoair filter paper were 77.3 Pa, 99.9941%, 3.50 μm, and 146 g/m², respectively, when the spinning time was 15 min.     

Image Interpolation via Gaussian-Sinc Interpolators with Partition of Unity

In this paper, we propose a novel image interpolation method by using Gaussian-Sinc automatic interpolators with partition of unity property. A comprehensive comparison is made with classical image interpolation methods, such as the bicubic interpolation, Lanczos interpolation, cubic Schaum interpolation, cubic B-spline interpolation and cubic Moms interpolation. The experimental results show the effectiveness of the improved image interpolation method via some image quality metrics such as PSNR and SSIM.     

Fabrication of silicon oxide nanodots with an areal density beyond 1 teradots inch(-2)

The combination of solvent annealing, surface reconstruction, and a tone-reversal etching procedure provides an attractive approach to utilize block copolymer (BCP) lithography to fabricate highly ordered and densely packed silicon oxide nano-dots on a surface. The obtained silicon oxide nano-dots feature an areal density of 1.3 teradots inch(-2) .     

A hierarchically structured and constraint-based data model for intuitive and precise solid modeling in a virtual reality environment

This article proposes a hierarchically structured and constraint-based data model for intuitive and precise solid modeling in a virtual reality (VR) environment. The data model integrates a high level constraint-based model for intuitive and precise manipulation, a middle level solid model for complete and precise representation and a low-level polygon mesh model for real-time interactions and visualization in a VR environment. The solid model is based on a hybrid B-rep/CSG data structure. Constraints are embedded in the solid model and are organized at hierarchical levels as feature constraints among internal feature elements, part constraints among internal features and assembly constraints between individual parts. In addition to providing a complete and precise model representation and the support for real-time visualization, the proposed data model permits intuitive and precise interaction through constraint-based manipulations for solid modeling in a VR environment. This is a critical issue for product design in a VR environment due to the limited resolutions of today's VR input and output devices.